NEET Biology

NEET Biology Multiple Choice Question and Answers

A Brief Account Of Evolution And Human Evolution

Question 1. How many eras does the geological time scale consist of?

1. Six
2. Five
3. Four
4. Three

Answer: 1. Six

The geological time scale is the tabulated form showing the sequence and duration of the eras and the periods with their dominant form of life since the beginning of life on the earth.

In the geological time scale, the duration of the earth’s history has been divided into six palaeoart geological timespans called the eras which are azoic, archaeozoic, proterozoic, palaeozoic, Mesozoic and Cenozoic.

Question 2. In which era, mammals and birds evolved?

1. Mesozoic
2. Cenozoic
3. Palaeozoic
4. Precambrian

Answer: 2. Cenozoic

” evolution class 12 mcq”
The Cenozoic era is the age of mammals, birds and angiosperms. The Mesozoic era is an age of reptiles and gymnosperms.

The Palaeozoic era is the age of amphibians and fishes. In the procambium era, the emergence of single-celled organisms occurred.

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Question 3. In Miocene,

1. Mammals reached a peak of diversity
2. Reptiles reached a peak of diversity
3. Reptiles were dominant
4. Birds were dominant

Answer: 1. Mammals reached a peak of diversity

In the Miocene epoch, mammals reached the peak of diversity as they occurred the evolution of the first man-like apes. Man is the most advanced mammal.

Question 4. Which of the following is not included in the Cenozoic era?

1. Devonian
2. Pliocene
3. Pleistocene
4. Miocene

Answer: 1. Devonian

The Devonian period belongs to a palaeozoic era which is famous as the ‘age of fishes. The rest of the options are included in the Cenozoic era.

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Question 5. Prevalence of only modern humans is observed in which epoch?

1. Pleistocene
2. Holocene
3. Pliocene
4. Miocene

Answer: 2. Holocene

In the quaternary period, there were two epochs The Holocene includes only modern humans. The Pleistocene includes the ice age and various human species.

Question 6. Dinosaurs became extinct in

1. Silurian period
2. Jurassic period
3. Triassic age
4. Cretaceous period

Answer: 4. Cretaceous period

Giant reptiles like dinosaurs became extinct in the Cretaceous period mainly because of their lack of adaptability, depleted supply of food, predation and large-scale destruction of their eggs.

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Question 7. The Mesozoic era is called the golden period of

1. Birds
2. Amphibians
3. Reptiles
4. Pisces

Answer: 3. Reptiles

The Mesozoic era is known as the golden age of the reptiles. It started about 252 million years ago when the Permian period came to an end and lasted until 65 million years ago when the Cretaceous period ended.

Question 8. The period of ……………… Were dominated by corals, lungfishes and air-breathing animals.

1. Mississippian
2. Silurian
3. Devonian
4. Jurassic

Answer: 2. Silurian

The Silurian period was dominated by corals, lungfishes and air-breathing animals. It was between 400-440 mya.

During this time, the appearance of the first terrestrial animals, wingless insects, jawed fishes, lycopods, and ferns occurred. There was also the dominance of algae, ascomycete fungi

Question 9. Mammals arose from reptiles in

1. Jurassic period of the Mesozoic era
2. Triassic period of mesozoic era
3. Cretaceous period of the Mesozoic era
4. Carboniferous age

Answer: 3. Cretaceous period of the Mesozoic era

Angiosperms and mammals arose simultaneously in the Cretaceous period of the Mesozoic era.

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Question 10. Trilobites appeared and disappeared, respectively during

1. Cambrian and permian period
2. Silurian and carboniferous period
3. Ordovician and triassic period
4. None of the above

Answer: 1. Cambrian and Permian periods

Trilobites are a well-known fossil group of extinct marine arthropods that form the class– Trilobita.

The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the early Cambrian period (526 million years ago).

They flourished throughout the lower Palaeozoic era before the beginning of a drawn-out decline to extinction when, during the Devonian, all Trilobite orders with the sole exception of Proetida died out.

Trilobites finally disappeared in the mass extinction at the end of the Permian about 250 million years ago.

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Question 11. The Jurassic period of the Mesozoic era was characterised by

1. Radiation of reptiles and origin of mammal-like reptiles
2. Dinosaurs became extinct and angiosperms appeared
3. Flowering plants and the first dinosaurs appeared
4. Gymnosperms were dominant plants and the first birds appeared

Answer: 4. Gymnosperms were dominant plants and the first birds appeared

The jurassic period of the Mesozoic era existed about 19-20 crore years ago and lasted for about 5.5- 6 crore years ago. The climate was hot and damp. It is called the Age of Dinosaurs. The first primitive bird archaeopteryx evolved from reptiles.

First angiosperm appeared as a dicotyledon, but gymnosperms were dominant in this era.

Question 12. In which era did protozoans, algae and sponges originate?

1. Cenozoic era
2. Azoic era
3. Proterozoic era
4. Mesozoic era

Answer: 3. Proterozoic era

In the proterozoic era, protozoan, algae and sponges originated.

Question 13. Which is the correct order of increasing geological time scale for a hypothetical vertebrate evolution?

1. Cenozoic, mesozoic, palaeozoic, precambrian
2. Cenozoic, palaeozoic, mesozoic, precambrian
3. Precambrian, cenozoic, palaeozoic, mesozoic
4. Precambrian, palaeozoic, Mesozoic, cenozoic

Answer: 4. Precambrian, palaeozoic, Mesozoic, Cenozoic

The correct order of increasing geological time scale for a hypothetical vertebrate evolution is Precambrian → palaeozoic → Mesozoic → Cenozoic Precambrian means hidden life, palaeozoic means old life, Mesozoic means middle life and Cenozoic means new life.

Question 14. Match the following columns.

 

Answer: 1–5, 2–4, 3–1, 4–3, 5–2

Question 15. Angiosperm arose in the …………………… Period.

1. Carboniferous
2. Cretaceous
3. Triassic
4. Tertiary

Answer: 2. Cretaceous

During the Cretaceous period of the Mesozoic era, there was rapid development of angiosperms (first monocotyledons) and a decline of gymnosperms

Question 16. Ancestral amphibians were tetrapods that evolved during

1. Jurassic period
2. Devonian period
3. Cretaceous period
4. Carboniferous period

Answer: 2. Devonian period

The Devonian period started about 405 million years ago and lasted about 60 million years ago.

It is frequently known as the ‘age of fishes. The late Devonian is characterised by the appearance of the first land vertebrates. These animals were amphibians and were called stegocepholians (roof-headed). The earliest known stegocepholian is named ichthyoses

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Question 17. The geological era extending from the present to 65 million years ago is called

1. Cenozoic
2. Mesozoic
3. Proterozoic
4. Palaeozoic

Answer: 1. Coenozoic

The Cenozoic era is the era of recent life up to the present, having an estimated duration of about 65 million years ago. It could be called as ‘age of mammals’ although it is also marked by great adaptive radiation in birds and insects.

Question 18. In which era life is absent?

1. Archaeozoic
2. Palaeozoic
3. Proterozoic
4. Azoic

Answer: 4. Azoic

The Azoic era is characterised by the complete absence of living organisms. This era can be described as the earliest time in the history of Earth during which several changes on Earth created favourable conditions for the appearance and preponderance of living organisms.

Question 19. The dominant animal during the Mesozoic era was

1. Pleiososaurus
2. Latimeria
3. Climatic
4. Ceratodus

Answer: 1. Pleiososaurus

The Mesozoic era is the geological era that extended from the end of the Palaeozoic era about 248 million years ago to the beginning of the Cenozoic era, about 65 million years ago. It comprises the Triassic, Jurassic and Cretaceous periods.

“questions about evolution “

The Mesozoic era is often known as the age of reptiles as these animals, which included the dinosaurs, pterosaurs, plesiosaurus and ichthyosaurus, became the dominant lifeforms.

Question 20. Which of the following statements is correct?

1. Birds originated 150 million years ago.
2. Mammals originated 200 million years ago.
3. Multicellular organisms originated 1 billion years ago.

Choose the option containing the correct statements.

1. 1 And 2
2. 2 And 3
3. 1 and 3
4. 1, 2 And 3

Answer: 4. 1, 2 And 3

All the given statements are correct. The basic timeline of the 4.6 billion-year-old earth, with the type of organisms, is given below

Age of appearance – types of organisms 3.6 billion years – simple cells (prokaryotes) 1 billion years – multicellular organisms 570 million years – arthropods (ancestors of insects, arachnids and crustaceans)

500 Million years – fish and proto amphibians
360 Million years – amphibians
300 Million years – reptiles
200 million years – mammals
150 million years – birds
20 million years – the appearance of the hominoidae (great apes)
Thus, option 4 is correct

Question 21. Identify the statements that are correct regarding the evolution of
plants and animals.

Amphibians evolved into reptiles.
Fish with stout and strong fins could move on land and go back to water. This happened about 350 million years ago.
Giant ferns fell to form coal deposits slowly.
About 65 million years ago, dinosaurs were wiped out.
Archaeopteryx is the connecting link between birds and reptiles. Choose the option containing the correct statements.

1 And 2
3 And 4
5 And 1
1, 2, 3, 4 And 5

Answer: 4. 1, 2, 3, 4 And 5

All the given statements are correct regarding the evolution of plants and animals.

Question 22. The dinosaurs were maximum during the period of

1. Jurassic
2. Triassic
3. Cretaceous
4. Palaeocene

Answer: 1. Jurassic

The Jurassic period of the Mesozoic era is known as the ‘golden age of dinosaurs. Dinosaurs were maximum during this period

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Question 23. Arrange the periods of a Palaeozoic era in ascending order of a geological time scale.

1. Cambrian → ordovician → silurian → devonian → carboniferous → permian
2. Cambrian → devonian → ordovician → silurian → carboniferous → permian
3. Cambrian → ordovician → devonian → silurian → carboniferous → permian
4. Silurian → devonian → cambrian ordovician → permian → carboniferous

Answer: 1. Cambrian → ordovician → silurian → devonian → carboniferous → Permian

The Palaeozoic (meaning the time of ancient life) era lasted from 544 to 245 million years ago and is divided into six periods.

Cambrian (541 million to 485.4 million years ago), Ordovician (485.4 million to 443.8 million years ago), Silurian (443.8 million to 419.2 million years ago),

Devonian (419.2 million to 358.9 million years ago), carboniferous (358.9 million to 298.9 million years ago) and Permian (298.9 million to 252.2 million years ago) periods. Thus, option 1 is correct

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Question 24. The age of fishes is also known as

1. Permian era
2. Silurian era
3. Devonian era
4. Ordovician era

Answer: 3. Devonian era

The Devonian is often appropriately called the age of fishes since the fish took their place in complex reef systems containing nautiloids, corals, graptolites, blastoids, echinoderms, trilobites, sponges, brachiopods and conodonts.

Question 25. Which of the following went extinct recently?

1. Draco
2. Dinosaur
3. Mammoth
4. Pteridosperms

Answer: 3. Mammoth

A mammoth is a species of the genus– Mammuthus which went extinct recently. They were commonly equipped with long, curved tusks and in northern species a covering of long hair is present.

They lived from the Pliocene epoch (from around 5 million years ago) to the Holocene, at about 4,500 years ago in Europe, Asia and america as far south as Mexico.

They were members of the family– Elephantidae which included, along with mammoths, two genera of modern elephants and their ancestors.

Question 26. First modern birds appeared during which era?

1. Jurassic
2. Cretaceous
3. Carboniferous
4. Triassic

Answer: 2. Cretaceous

The first modern birds appeared during the Cretaceous period

Question 27. In which period of the palaeozoic era did the first vertebrates appear?

1. Silurian
2. Ordovician
3. Devonian
4. Mississippian

Answer: 2. Ordovician

It was long thought that the first true vertebrates (fish – ostracoderm) appeared in Ordovician, but recent discoveries in China reveal that they probably originated in the early Cambrian.

The very first gnathostome (jawed fish) appeared in the late Ordovician epoch

Question 28. The gymnosperms formed the dominant vegetation on the earth during the geological period called

1. Carboniferous
2. Permian
3. Triassic
4. Jurassic

Answer: 3. Triassic

Gymnosperms are a small group of plants which constitute a subdivision of spermatophyte or phanerogams.

Gymnosperms are the most primitive seed plants. The age of higher gymnosperms is the Mesozoic era. The forest of the Triassic period of the Mesozoic era was formed of highly developed gymnosperms, represented chiefly by conifers and cycads.

Question 29. The occurrence of endemic species in South America and Australia is due to

1. These species have been extinct in other regions
2. Continental separation
3. There is no terrestrial route to these places
4. Retrogressive evolution

Answer: 2. Continental separation

The presence of endemic species (monotremes and marsupials) in Australia and south america is due to continental separation.

Australia, New Zealand and south america were once continuous with the mainland of Asia but got separated in the late Cretaceous period before the appearance of carnivorous Eutherian mammals.

Placental mammals, being more adapted, eliminated monotremes and most marsupials from the Asian mainland, but the primitive mammals of Australia and south america survived, as placental mammals could not reach there because of no land connections.

Question 30. The era called the ‘Age of prokaryotic microbes’ is

1. Archaeozoic
2. Precambrian
3. Phanerozoic
4. Proterozoic

Answer: 4. Proterozoic

About one billion years ago, the dominant organisms of Earth were cyanobacteria and protozoans therefore, it was named ‘proterozoic’. It is known as the age of prokaryotic microbes

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Question 31. Match the following columns. 

Answer: 2. 1-5,2-1,3-4,4-2

Question 32. In the Mesozoic era, the correct sequence of the periods, beginning with the earliest, is

1. Triassic, Jurassic, cretaceous
2. Jurassic, cretaceous, Triassic
3. Cretaceous, Triassic, and Jurassic
4. Cretaceous, Jurassic, Triassic

Answer: 1. Triassic, Jurassic, cretaceous

In the Mesozoic era, the correct sequence of the periods beginning with the earliest is triassic→ Jurassic → Cretaceous

Question 33. The geologic time scale was developed by

1. Aristotle
2. C Lapworth
3. A Sedgwick
4. G Arduino

Answer: 4. G Arduino

The first geological time scale was developed by Giovanni Arduino, an Italian scientist, in 1760

Question 34. The origin of the first toothed birds took place in

1. Cretaceous
2. Triassic
3. Jurassic
4. Permian

Answer: 3. Jurassic

The jurassic era occurred from 199.6 to 145.5 million years ago. The reptiles are evident to have dominated this era and so, the existence of first-toothed birds is believed to have occurred during the Jurassic era.

Question 35. The first evidence of land plants came in

1. Archeozoic era
2. Mesozoic era
3. Palaeozoic era
4. Cenozoic era

Answer: 3. Palaeozoic era

The first land plants appeared around 470 million years ago, during the Ordovician period when life was diversifying rapidly. They were non-vascular plants like mosses and liverworts, that did not have deep roots. Ordovician period is a part of palaeozoic era.

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Question 36. During the course of evolution, which part of the brain has shown maximum increase in size?

1. Midbrain
2. Forebrain
3. Hindbrain
4. All of these

Answer: 2. Forebrain

The forebrain is the brain region which has undergone the most dramatic changes through vertebrate evolution. So, it has shown a maximum increase in size. It controls body temperature, reproductive functions, eating, sleeping and the display of emotions

Question 37. Primates which existed about 15 million years ago were

1. Dryopithecus
2. Homo habilis
3. Ramapithecus
4. Australopithecus

Answer: ramapithecus

Ramapithecus was a primate which appeared about 14-15 million years ago.

Question 38. Man evolved in

1. Triassic period
2. Jurassic
3. Permian period
4. Pliocene

Answer: 4. Pliocene

Pliocene is characterised by the origin of man. Triassic involved the evolution of various reptilian groups like dinosaurs, pterosaurs and ichthyosaurus.

Question 39. The age of the fossil of Dryopithecus on the geological time scale is

1. 5 × 106 Years back
2. 25 × 106 Years back
3. 50 × 106 Years back
4. 75 × 106 Years back

Answer: 2. 25 × 106 Years back

Dryopithecus lived about 20- 25 million years ago or 25 10× 6 years back

Question 40. In recent years, dna sequences (nucleotide sequences of mtDNA and y-chromosomes) were considered for the study of human evolution, because

1. Their structure is known in greater detail
2. They can be studied from the sample of fossil remains
3. They are small and therefore easy to study
4. They are uniparental in origin and do not take part in recombination

Answer: 4. They are uniparental in origin and do not take part in recombination

Wilson and Sarich chose mitochondrial dna (mtDNA) for the study of material line inheritance, while chromosomes were considered for the study of human evolution, particularly of the male domain.

It is possible because they are uniparental in origin and do not take part in recombination.

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Question 41. What kind of evidence suggested that man is more closely related to chimpanzees than to other hominoid apes?

1. Evidence from dna from sex chromosomes only
2. Comparison of chromosome morphology only
3. Evidence from fossil remains, and the fossil mitochondrial dna alone
4. Evidence from dna extracted from sex chromosomes, autosomes and mitochondria

Answer: 4. Evidence from dna extracted from sex chromosomes, autosomes and mitochondria

Question 42. The cranial capacity of Neanderthal man is

1. 1350-1500 Cm3
2. 1400-1450 Cm3
3. 915-1250 Cm3
4. 750-900 Cm3

Answer: 1400-1450 cm3

Question 43. Neanderthal man was followed by

1. Cro-magnon man
2. Homo sapiens sapiens
3. Homo erectus
4. Homo neanderthalensis

Answer: 4. Homo neanderthalensis

Dna from sex chromosomes, autosomes and mitochondria reflect the entire genomic limit. The degree of similarities between two species can be estimated by the pairing property of dna strands.

In the case of man and chimpanzee, there is 100% pairing between sex chromosome dna and autosomal dna.

Question 44. There are two opposing views about the origin of modern man. According to one view homo erectus in Asia were the ancestors of modern man. A study of variation of dna however suggested the African origin of modern man. What kind of observation on dna variation could suggest this?

1. Greater variation in Asia than in Africa
2. Greater variation in Africa than in Asia
3. Similar variations in Africa and Asia
4. Variation only in Asia and no variation in Africa

Answer: 1. Greater variation in Asia than in Africa

Scientists studying mitochondrial dna from living humans all over the world have argued that their research shows that all human races originated from one homo sapiens ancestor in Africa.

The divergence of mitochondrial dna of Africans from common sources began just some years back which was late for homo erectus to split between Asia.

Thus, there is greater variation in Asia than in Africa

Question 45. Among the human ancestors, the brain size was more than 1000 cc in

1. Homo erectus
2. Ramapithecus
3. Homo habilis
4. Homo neanderthalensis

Answer: 4. Homo neanderthalensis

Homo habilis had a cranial capacity in the range of 680 – 720 cc and that of homo erectus erectus was 775 – 990 cc. Homo erectus pekinensis had 915-1200 cc. Homo neanderthalensis had 1300-1600 cc.

Question 46. Choose the statement that is incorrect about homo habilis.

1. Also called an able or skilful man.
2. Also called a tool maker.
3. Fossils were discovered from fast Africa.
4. 500 Cc brain size.
5. Have teeth like a modern man.
6. Lived 2 million years ago.

Choose the correct option.

1. Only 4
2. Only 5
3. Only 2
4. Only 4

Answer: 1. Also called able or skilful man.

Only statement iv is incorrect. Homo habilis is also called handy or toolmaker man. Mary Leaky and lbs Leaky discovered the fossils of homo habilis from Pleistocene rocks of Olduvai Gorge in East Africa. His cranial capacity was 680-720 cc.

Their teeth were like that of modern humans. They were called able or skilful men and lived 2 million years ago. Rest statements are correct about homo habilis.

Question 47. What was the most significant trend in the evolution of modern man (homo sapiens) from his ancestors?

1. Upright posture
2. Shortening of jaws
3. Binocular vision
4. Increasing brain capacity

Answer: 4. Increasing brain capacity

The most significant trend in the evolution of modern man (Homo sapiens) from his ancestors is the increase in brain capacity.

Question 48. The extinct human who lived 1,00,000 to 40,000 years ago, in Europe, Asia and parts of Africa, with short stature, heavy eyebrows, retreating foreheads, large jaws with heavy teeth, stocky bodies, a lumbering gait and stooped posture was

1. Homo habilis
2. Neanderthal human
3. Cro-magnon man
4. Ramapithecus

Answer: 4. Ramapithecus

The most significant trend in the evolution of modern man (homo sapiens) from his ancestors is the increase in brain capacity.

Question 49. Genus–homo erectus includes three fossil(s) namely

1. Java ape man
2. Neanderthal man
3. Cro-magnon man
4. Peking man
5. Heidelberg man
6. Modern man

Choose the correct option.

1. 1, 2 And 3
2. 2, 4 And 5
3. 1, 4 And 5
4. 3, 4 And 5

Answer: 3. 1, 4 And 5

Homo erectus includes three fossils (1, 4, 5)

java ape man- body 1.65 to 1.75 m tall, weight 70 kg, cranial capacity 800 to 1000 cc. peking man- about 1.55 to 1.60 m tall. He was slightly shorter and weaker.

He had a cranial capacity which ranged from 850 to 1100 cc. heidelberg man- he used tools and fire.

Cranial capacity was believed to be about 1300 cc. It is regarded as an intermediate between pithecanthropines and Neanderthals

Question 50. The modern man differs from the apes in

1. Protruding eyes
2. Spare body hair
3. Wearing of clothes
4. Arms shorter than legs

Answer: 4. Arms shorter than legs

Modern man differs from the apes in arms are shorter than legs, and apes’ arms are used in locomotion, called brachiating. This is a type of suspension and swinging of the body

Question 51. Which of the following is closer to man?

1. Proconsul
2. Dryopithecus
3. Gibbon
4. Orangutan

Answer: 2. Dryopithecus

Dryopithecus are more close to man. Their canine teeth are larger than those in humans, but not as strongly developed as those in other living apes. The limbs were not excessively long.

The skull lacked the well-developed crests and massive brow ridges similar to man

Question 52. Which one of the following statements about the fossil human species is correct?

1. Fossils of homo neanderthalensis have been found recently in south america
2. Neanderthal man and cro-magnon man did exist for some time together
3. Australopithecus fossils have been found in Australia
4. Homo erectus was preceded by homo habilis

Answer: 4. Homo erectus was preceded by homo habilis

The statement in option 4 is correct about the fossil human species. Other statements are incorrect and can be corrected as Cro-magnon succeeded Neanderthal.

Thus, they did not exist together. Fossils of Neanderthal man have been found in Europe, Asia and North Africa. Fossils of Australopithecus have been found in Africa.

Question 53. Which human ancestor was named Lucy?

1. Heidelberg man
2. Cro-magnon man
3. Australopithecus africanus
4. Ramapithecus punjabicus

Answer: 3. Australopithecus africanus

In 1981, Donald Johanson found a 3.2 million-year-old skeleton of a female human ancestor. He nick-named it, Lucy. Lucy’s scientific name is Australopithecus africanus.

Question 54. Which one of the following statements is correct?

1. Cro-magnon man’s fossil has been found in Ethiopia
2. Homo erectus is the ancestor of man
3. Neanderthal man is the direct ancestor of homo sapiens
4. Australopithecus is the real ancestor of modern man

Answer: 2. Homo erectus is the ancestor of man

Only the statement in the option is correct. Other statements are incorrect and can be corrected as Cro-magnon man’s fossils have been found in Europe.

Neanderthal man is a transitional stage and it is not the direct ancestor of homo sapiens. Australopithecus appeared in the early Pleistocene and it is not the real ancestor of modern man

Question 55. Which of the following terms clearly determines the boundary between pieces and homo?

1. Erect posture and free hands
2. Reduced jaws and bipedal locomotion
3. Parabolic dental arch
4. Increased cranial capacity and skilful manipulation of hands to make tools

Answer: 4. Increased cranial capacity and skilful manipulation of hands to make tools

Dryopithecus, ramapithecus and Australopithecus, all had small cranial capacity and did not make tools. But homo habilis, homo erectus and homo sapiens, all had cranial capacity of more than 650 cc and started making tools.

Therefore, we can say that increased cranial capacity and skilful manipulation of hands to make tools determines the boundary between pieces and homo.

Question 56. The chronological order of human evolution from early to the recent stages is

1. Ramapithecus → Australopithecus → homo habilis → homo erectus
2. Australopithecus → ramapithecus → homo habilis → homo erectus
3. Pithecanthropus pekinensis → homo habilis → homo erectus
4. Australopithecus → ramapithecus → pithecanthropus pekinensis → homo erectus

Answer: 1. Ramapithecus → Australopithecus → homo habilis → homo erectus

The chronological order of human evolution is ramapithecus (first hominid) → Australopithecus (first ape-man) → homo habilis (tool maker handyman) → homo erection

Question 57. Match the following columns.

Answer: 2. 1–4, 2–3, 3–2, 4–1

Question 58. The first human fossil probably belonged to

1. Zizanthropus
2. Australopithecus
3. Pleisanthropus
4. Pithecanthropus

Answer: 2. Australopithecus

Australopithecus is a group of extinct primates, closely related to (not actually ancestors) modern human beings and known from a series of fossils found at numerous sites in eastern, north-central and southern Africa.

Therefore, we can say the first human fossil probably belonged to Australopithecus.

Question 59. Which one of the following is the most primitive ancestor of man?

1. Homo habilis
2. Australopithecus
3. Ramapithecus
4. Homo neanderthalensis

Answer: 3. Ramapithecus

Ramapithecus (pithecus ape) lived about 14-8 mya. It was the most primitive human ancestor and a small ape-like creature (14 kg) which probably walked upright.

Question 60. Who was the first civilised man?

1. Cro-magnon man
2. Neanderthal man
3. Heidelberg man
4. Ternifier man

Answer: 1. Cro-magnon man

Cro-magnon was an excellent tool maker and a fine artist as they drew pictures in their caves. They were the first to domesticate dogs. They were also religious. So, they were the first civilised man.

Question 61. Homo sapiens originated how many years ago?

1. About 5 lakh years ago
2. About 2 lakh years ago
3. About 4 lakh years ago
4. About 3 lakh years ago

Answer: 2. About 2 lakh years ago

So far, the earliest finds of modern homo sapiens skeletons come from Africa. They date to nearly 2,00,000 years ago on that continent

Question 62. Fossil man, who made cave painting was Bihar

1. Java man
2. Neanderthal man
3. Cro-magnon
4. Peking man

Answer: 3. Cro-magnon

Cro-magnon man (homo sapiens fossilis) made cave paintings.

Cro-magnon was an excellent tool maker and a fine artist as they drew pictures in their caves. They were the first to domesticate dogs. They were also religious. So, they were the first civilised man.

Question 63. The ancestor of the man who first stood erect was

1. Java man
2. Australopithecus
3. Peking man
4. Cro-magnon

Answer: 1. Java man

‘Homo erectus’ (java man) is called ‘upright man’ (stood erect). So, it first stood erect.

Question 64. The most recent and direct pre-historic ancestor of present man is

1. Cro-magnon
2. Pre-neanderthal
3. Neanderthal
4. None of these

Answer: 1. Cro-magnon

Cro-magnon was the recent and direct pre-historic ancestor of the present man. They are referred to as early modern humans who lived in our world at the end of the last ice age (40,000-10,000 years ago).

Question 65. Homo erectus is the zoological name of

1. Cro-magnon man
2. Peking man
3. Nutcracker man
4. Neanderthal man

Answer: 2. Peking man

Peking man (homo erectus pekinensis, formerly known by the junior synonym, Sinanthropus pekinensis) is a group of fossil specimens of homo erectus, dated from roughly 7,50,000 years ago.

It was discovered in 1923-27 during excavations at Zhoukoudian near Beijing (at the time spelt Peking), china.

Question 66. Which primitive man used stones to produce fire?

1. Java ape man
2. Neanderthal man
3. Cro-magnon man
4. All of the above

Answer: 1. Java ape man

At Trinil, java, burned wood had been found in layers that carried h. Erectus (java man) fossils dating from 8,30,000 to 5,00,000 bp. The burned wood has been claimed to indicate the use of fire by early hominids.

Question 67. Java ape man is considered to have existed in

1. Java only
2. China only
3. Africa only
4. Java, China and Africa

Answer: 4. Java, China and Africa

Java ape-man existed in Java, China and Africa.

Question 68. Dubois, in 1891 found the fossil of Java ape-man. It is

1. Sinanthropus pekinensis
2. Homo erectus
3. Homo rhodesiensis
4. Homo sapiens

Answer: 4. Homo sapiens

Homo erectus erectus (java ape man) was excavated in 1891 by Dubois from the rocks of central Java.

Question 69. Assertion among the primates, the chimpanzee is the closest relative of present-day humans. Reason (r) the banding pattern in the autosome numbers 3 and 6 of man and chimpanzee is remarkably similar.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r is false
4. Both a and r are false

Answer: 1. Both a and r are true and r is the correct explanation of a

It has been observed that the banding pattern of individual human chromosomes is very similar to the banding pattern of the corresponding chromosomes in apes.

The banding pattern of human chromosomes number 3 and 6 was compared with those of particular autosomes in the chimpanzee. It shows a common origin for man and chimpanzee

Question 70. Fossils of Australopithecus were first found in Punjab

1. America
2. Australia
3. S. Africa
4. Asia

Answer: 3. S. Africa

Australopithecus fossils were discovered in 1920 by Prof. Raymond from tanks in South Africa.

Australopithecus is a genus of fossil primates that lived 4-2 million years ago and coexisted for some of this time with early forms of humans.

They walked erect and had teeth resembling those of modern humans, but the cranial capacity was less than one-third that of a modern human.

Question 71. The ancestor of the man who first exhibited bipedal gait

1. Australopithecus
2. Cro-magnon man
3. Java ape man
4. Peking man

Answer: 1. Australopithecus

Australopithecus is also called the first ape-man. Some of its characteristics are as follows They were about 1.5 m tall and had human as well as ape characters. They possessed bipedal locomotion, omnivorous diet and had erected posture.

Their cranial capacity was about 500 cc, similar to that of apes. They lived in caves. They had the lumber curve in their back.

They hunted with simple weapons like stones. They lived in Africa region about 3.2 mya.

Question 72. The scientific name of Soloman is

1. Homo stenosis
2. Neanderthal
3. Ramapithecus
4. Homo erectus

Answer: 1. Homo stenosis

Home stenosis is the scientific name of Soloman

Question 73. Who first discovered fossils of ‘ramapithecus’?

1. Dubois
2. R dart
3. Ge lewis
4. Jk fuhlort

Answer: 3. Ge lewis

Ramapithecus was discovered in n. India and in e. Africa, beginning in 1932. It was discovered by George Lewis.

Question 74. Which one of the fossil men stood first?

1. Australopithecus
2. Homo erectus
3. Sinanthropus
4. Gigantopithecus

Answer: 2. Homo erectus

‘Homo erectus’ (java man) is called ‘upright man’ (stood erect). So, it first stood erect

Question 75. The lowest capacity of the cranium was found in the

1. Neanderthal man
2. Australopithecus
3. Cro-magnon man
4. Java man

Answer: 2. Australopithecus

Out of the given options, the lowest brain capacity is found in Australopithecus, ranging from 450-600 cc or slightly above

Question 76. Which one is called ‘a man with ape brain’?

1. Dryopithecus
2. Pithecanthropus
3. Sinanthropus
4. Australopithecus

Answer: 4. Australopithecus

Australopithecus were the ancestors of humans with the ape brain, whose brains were in the process of development

Question 77. Human beings belong to the family–Hominidae which evolved about 24 million years ago. The relative family–Pongidae includes

1. Chimpanzee
2. Gorilla
3. Orangutan
4. All of these

Answer: 4. All of these

The Hominidae (also known as great apes) form a taxonomic family of primates, including four genera

1. Chimpanzees
2. Gorillas
3. Humans (homo)
4. Orangutans (pongo)

Question 78. Handy man is

1. Cro-magnon
2. Neanderthal
3. Homo habilis
4. None of the above

Answer: 3. Homo habilis

Homo habilis is called handyman because researchers believe this species of human ancestors were the first primates to use tools, leaving evidence of stone tools at various archaeological sites.

Question 79. Which one of the following is considered a common ancestor of old world monkeys, apes and man?

1. Oligopithecus
2. Shivapithecus
3. Ramapithecus
4. Parapithecus

Answer: 3. Ramapithecus

Ramapithecus is an extinct group of primates that lived about 12 to 14 million years ago. Thus, it is considered a common ancestor of old-world monkeys, apes and man.

Question 80. Which of the following statement is correct about homo erectus?

1. Had a large brain of around 900 cc.
2. Appeared about 1.5 million years ago.
3. Ate meat.
4. Evolved from homo habilis.

Choose the correct option.

1. 1 And 2
2. 3 And 4
3. 1, 2, 3 And 4

Answer: 4. 1, 2, 3 And 4

All given statements are correct. Features of homo erectus are as follows They appeared about 1.5-1.7 million years ago.

They evolved from homo habilis. They were about 1.5-1.8 m long. Their cranial capacity was 800- 1300 cc, cranium was domed to accommodate large brains. They ate me

Question 81. The biological name of the Java man is

1. Homo erectus erectus
2. Anthropopithecus erectus
3. Pithecanthropus erectus
4. All of the above

Answer: 4. All of the above

Ava man (homo erectus erectus, formerly also anthropopathic’s erectus, Pithecanthropus erectus) is an early human fossil discovered in 1891 and 1892 on the island of Java (dutch east indies, now part of Indonesia).

Question 82. The cranial capacity of Java ape was about

1. 560 Cc
2. 900 Cc
3. 1300 Cc
4. 1600 Cc

Answer: 2. 900 Cc

The cranial capacity of Java ape was about 900 cc.

Question 83. Proper burial of dead bodies, for the first time started in which prehistoric man’s period?

1. Peking man
2. Java man
3. Neanderthal man
4. Cro-magnon man

Answer: 3. Neanderthal man

Neanderthal buried the dead bodies with flowers and tools.

Question 84. Which is the correct chronological sequence of human evolution?

1. Ramapithecus → Australopithecus → homo erectus neanderthalensis → homo sapiens
2. Ramapithecus → homo habilis → homo sapiens → homo erectus
3. Australopithecus → ramapithecus → homo habilis → homo sapiens
4. Homo habilis → australopithecus → homo erectus → homo sapiens

Answer: 4. Homo habilis → Australopithecus → homo erectus → homo sapiens

The correct chronological sequence of human evolution is ramapithecus →australopithecus → homo erectus neanderthalensis → homo sapiens

Question 85. The fossils of homo habilis were discovered by Leaky et al. (1964) In

1. Germany
2. Europe
3. Australia
4. Africa

Answer: 4. Mary Leaky and lbs Leaky discovered the fossils of homo habilis from Pleistocene rocks of Olduvai Gorge in East Africa

Question 86. Match the following columns.

Answer: 4. 1–4, 2–3, 3–1, 4–2

Question 87. The evolution of man took place in

1. Central Africa
2. Central Asia
3. Australia
4. America

Answer: 1. Central Africa

The evolution of man took place in central Africa. It is considered that the common ancestor of both humans and apes, Dryopithecus was found in the Miocene rock of Africa and Europe.

Question 88. Identify the cranial capacity a, b and c of the given primates.
Primates → cranial capacities (in cubic centimetres)

1. Chimpanzee and gorilla → a
2. Australopithecus → 500 cc
3. Homo habilis → b
4. Java ape-man → 800-1000 cc
5. Heidelberg man → c

Choose the correct option

1. A–325-500 cc, b–900 cc, c–800- 1000 cc
2. A–325-510 cc, b–700 cc, c–1300 cc
3. A–325-510 cc, b–700 cc, c–850- 1200 cc
4. A–325-510 cc, b–700 cc, c–850- 1400 cc

Answer: 2. Australopithecus → 500 cc

The cranial capacities of apes and man are Chimpanzee and gorilla → 325-510 cc (a) Homo habilis – 700 cc (b) Heidelberg man →1300 cc (c)

Question 89. A cranial capacity of 1200 cc belongs to

1. Java man
2. Peking man
3. Cro-magnon man
4. Both 1 and 2

Answer: 2. Peking man

Peking man is homo erectus pekinensis and it was discovered near Peking (china). Their brain size was 1200 cc.

Question 90. Which of the following presumably possesses a cranial capacity larger than modern man?

1. Neanderthal man
2. Peking man
3. Australopithecus
4. Cro-magnon man

Answer: 4. Cro-magnon man

Cro-magnon were the first humans (genus–homo) to have a prominent chin. The brain capacity was about 1600 cc (100 cubic inches), somewhat larger than the average as compared to modern humans

Question 91. The oldest human ancestral fossil discovered from the rocks of the Oligocene epoch is called

1. Dryopithecus
2. Ramapithecus
3. Parapithecus
4. Cro-magnon

Answer: 3. Parapithecus

Parapithecus fossils were the oldest human ancestral fossils discovered in 1911 from Egypt, in the Oligocene epoch

Question 92. The epoch of the beginning of human life is

1. Palaeocene
2. Pleistocene
3. Pliocene
4. Holocene

Answer: 3. Pliocene

Pliocene is characterised by the origin of man. Thus, it is the epoch of the beginning of human life.

Question 93. Which of the following is the major change during human evolution?

1. Formation of a rounded head, vertical forehead and flat face
2. Reduction in the size of eyebrows ridges, formation of elevated nose and prominent chin
3. Erect posture and bipedal locomotion
4. All of the above

Answer: 4. All of the above

All the given options represent changes during human evolution. Thus, option 4 is correct.

Question 94. Which of the following was not in the direction of the evolution of the human species?

1. Raised orbital ridges
2. Binocular vision
3. Developed brain
4. Opposable thumb

Answer: 1. Raised orbital ridges

Raised orbital ridges are not in the direction of the evolution of the human species.

Question 95. Anthropoids evolved into

1. Apes, proconsul and monkeys
2. Apes, cro-magnon men and old-world monkeys
3. Proconsul, New World Monkeys and Peking man
4. New world monkeys, proconsul and homo habilis

Answer: 1. Apes, proconsul and monkeys

Anthropoids are like human beings or an ape. Anthropoid gorillas, chimpanzees and gibbons, are all anthropoid apes, having long arms, no tails and highly developed brains.

Thus, monkeys, apes and proconsul, are all anthropoids.

Question 96. The difference between homo sapiens and the homo erectus was

1. Homo sapiens originated in Africa, while homo erectus originated in Asia
2. Homo erectus were much smaller in size than homo sapiens
3. Homo erectus stayed in Africa, while homo sapiens were nomads
4. The size of the brain of homo erectus was smaller than that of homo sapiens

Answer: 4. The size of the brain of homo erectus was smaller than that of homo sapiens

Homo erectus were Java men with cranial capacity 800-1000 cc. Homo sapiens are living modern men with a cranial capacity of 1450 cc. Thus, the brain size of homo erectus was smaller than that of homo sapiens.

Question 97. The most recent in human evolution is

1. Mesolithic
2. Neolithic
3. Upper palaeolithic
4. Middle palaeolithic

Answer: 2. Neolithic

Neolithic is also called the age of agriculture. It is the most recent time of evolution in human

Evolution Mcq For NEET

Question 98. The rise of ist primates occurred in …………………. Epoch.

1. Palaeocene
2. Oligocene
3. Miocene
4. Eocene

Answer: 1. Palaeocene

The first primate-like mammals, or proto-primates, evolved in the early palaeocene epoch (65.5-55.8 million years ago), at the beginning of the Cenozoic era.

They were roughly similar to squirrels and tree shrews in size and appearance.

Question 99. Which of the following is the closest relative of man?

1. Orangutan
2. Gorilla
3. Sinanthropus
4. Gibbon

Answer: 3. Sinanthropus

Misanthropes (from Sino-China and anthro-man) is an archaic genus in the scientific classification system to which the early hominid fossils of Peking man belong.

They have now been reclassified as Homo erectus. The genus– Sinanthropus is now disused but it is still known as the closest relative of man. The other three are apes.

Question 100. Apes and hominids have evolved from

1. Dryopithecus
2. Australopithecus
3. Homo erectus
4. Homo habilis

Answer: 1. Dryopithecus

Dryopithecus is the oldest human-like fossil. It is considered the common ancestor of both hominids and apes. Dryopithecus was found in Miocene rock of Africa and Europe

Question 101. Match the following columns.

Answer: 3. A–2, b–1, c–3, d–4

Question 102. Match the following columns.

Answer: 2. A–4, b–3, c–2, d–1

Question 103. Assertion almost 100% of the genetic makeup of man is similar to chimpanzees. Reason (r) 94% genetic makeup of man and gibbon is similar.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r is false
4. Both a and r are false

Answer: 4. Both a and r are false

These can be corrected as the analysis of the sequence of 7100 nucleotides in a segment of dna from the haemoglobin gene suggests that humans and chimpanzees are closer to one another than chimpanzees and gorillas.

They matched at 98.8% of the bases in man and chimpanzee and 97.9% with gorilla and man.

The gibbons are sufficiently different to be in their own family of hominids, the Hylobatidae. Along with the great apes, humans are members of the family Hominidae.

Of all living species, people are genetically and evolutionarily closest to the African apes. Subsequently, they have been placed into the same subfamily, the homininae. The genetic similarity between man and gibbons is less than 94%.

Question 104. Assertion Neanderthal man was more intelligent than other fossil relatives. Reason (r) it had the largest cranial capacity.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r is false
4. Both a and r are false

Answer: both a and r are true and r is the correct explanation of a

The Neanderthal man is considered the most intelligent man as compared to the other relatives of ancient man such as fossils of homo erectus.

The cranial capacity of the Neanderthal man was 1600 cm3, which is higher when compared to the cranial capacity of the modern man, which is 1400 cm3.

This is the reason that these men were considered more intelligent.

Question 105. Consider the following statements.

Java men and Peking men were called homo erectus by Mayer.
They both did not use fire.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 1. Statement 1 is correct, but 2 is incorrect

Bhomo erectus evolved from the homo habilis and were divided into three groups called the Java man, Peking man and Heidelberg man.

Java men and Peking men have the same characteristics like using fire, living in the same caves, body length, omnivorous and cannabis. But the only difference was in the capacity of the cranium.

Evolution Mcq For NEET

Question 106. Assertion southern ape is called the connecting link between ape and man. Reason (r) This is an Australopithecus who had combined features of ape and man.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r is false
4. Both a and r are false

Answer: 1. Both a and r are true and r is the correct explanation of a.

Southern ape is called a connecting link between ape and man. It is first with fully bipedal hominids, with small brains, short stature, and heads balanced on the neck.

Thus, Australopithecus had combined features of ape and man

Question 107. Match the hominids with their correct brain size.

Answer: 3. A–3, b–4, c–1, d–2

Question 108. Hominids originated during

1. Palaeocene
2. Pliocene
3. Miocene
4. Oligocene

Answer: 3. Miocene

The term hominid refers to humans and their direct and near-direct bipedal ancestors. Hominids originated during the Miocene epoch.

Question 109. Consider the following statements.

From an evolutionary point of view, the human gestation period is believed to be shortening.
One major evolutionary trend in humans has been the larger head undergoing a relatively faster growth rate in the foetal stage.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 2. Statement 1 is incorrect, but 2 is correct

The incorrect statement can be corrected as the humans would require more gestation period (should have been 21 months as compared to 9 months and will increase) because the head size is increasing (especially the frontal brain).

Hence, the growth rate needs to be increased, but surprisingly most of the brain growth occurs after birth till 2 years (when the anterior fontanelle closes at 18 months) and even more till 30 years when the cranial sutures close.

Thus, an increase in brain/skull size would require an increase in the gestation period.

Question 110. Assertion human ancestors never used their tails and so the tail-expressing gene has disappeared in them. Reason (r) Lamarck’s theory of evolution is popularly called the theory of continuity of germplasm.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is false, but r is true
4. Both a and r are false

Answer: 4. Both a and r are false and can be corrected as if humans share ancestry with primates, then we should expect to see remnants of that common ancestry in our genes.

For example, the tail is occasionally exhibited in atavism. According to current evolutionary theory, the ancestors of humans lost their tails about 25 million years ago, when apes (tailless primates) diverged from monkeys (tailed primates) secondly, the theory of continuity of the germplasm was given by Weismann

Question 111. Proconsuls are ancestors of

1. Apes only
2. Man only
3. Both apes and man
4. None of these

Answer: 3. Both apes and man

Proconsul africanus is an ancestor of both apes and early humans that lived about 25 million years ago.

Question 112. Which of the following shows the smallest cranial capacity?

1. Rhesus monkey
2. Orangutan
3. Chimpanzee
4. Gorilla

Answer: 2. Orangutan

Orangutan has the smallest cranial capacity in comparison to rhesus monkey, chimpanzee and gorilla.

Evolution Mcq For NEET

Question 113. The tailless primate is

1. Lemur
2. African baboon
3. Spider monkey
4. Loris

Answer: 4. Loris

Loris is found outside Madagascar. Slender loris, loris tardigrades, is seen in southern India and Sri lanka, while Nycticebus bengalensis is from northern India.

Like lemurs, they also eat fruits and small animals. However, they are tailless, move slowly and often hang upside down.

Question 114. Neanderthal man became extinct due to

1. Earthquakes
2. Forest fire
3. Competition
4. Origin of active mammals

Answer: 3. Competition

Mousterian technologies, the sudden appearance of modern homo sapiens, upper palaeolithic technologies and the absence of transitional anatomical or technological forms have led many researchers to conclude that Neanderthal was driven to extinction through competition with cro-magnon or related populations. Hence, option 3 is correct.

Question 115. Peking Man is known

1. Australopithecus
2. Sinanthropus
3. Pithecanthropus
4. Homo sapiens

Answer: 2. Sinanthropus

Wc Pei (1924) discovered the fossils of Peking man from the limestone caves of Choukoutien near Peking (Beijing – the capital of China and formerly known as Peking) and named them Sinanthropus.

Davidson Black (1927) named it Sinanthropus pekinensis. Mayer (1950) renamed it homo erectus pekinensis (a subspecies).

Question 116. Man’s Place in Nature was written by

1. Huxley
2. Darwin
3. Dawson
4. Dart

Answer: 1. Huxley

Man’s Place in Nature is a book by Thomas Henry Huxley published in 1863, in which he gave evidence for the evolution of man and apes from a common ancestor. It was the first book that covered the topic of human evolution

Question 117. Who coined the term ‘homo sapiens’?

1. Charles darwin
2. Lamarck
3. Carolus linnaeus
4. Lederberg

Answer: 3. Carolus linnaeus

The species binomial ‘homo sapiens’ was coined by Carolus Linnaeus in his 18th-century work, Systema Naturae.

Question 118. ‘The Descent of Man was published by

1. Charles Darwin in 1871
2. Charles Darwin in 1859
3. Hugo de vries in 1901
4. Lamarck in 1809

Answer: 1. Charles Darwin in 1871

‘The Descent of Man’ was published on 24th February 1871 and was written by Charles Darwin. It is a book on sexual selection and evolutionary biology

Biology MCQ For NEET With Answers Origin Of Life

Question 1. What does evolutionary biology refer to?

1. The study of the history of life forms on earth
2. Study of pedigrees of life forms on earth
3. It is equivalent to demography
4. It is equivalent to anthropology

Answer: 1. The study of the history of life forms on earth

Evolutionary biology is the study of the history of life forms on Earth. The word ‘evolution’(Latin-volvere) means to unfold or unroll. In a broad sense, evolution simply means an orderly change from one condition to another.

Evolution is a continuous process in which progeny with modification is produced.

“evolution neet mcqs “

Question 2. What is observed in evolution?

1. A sudden change occurring in a population
2. Progeny with modifications
3. It is a discontinuous process
4. All of the above

Answer: 2. Progeny with modifications

The term evolution means that living beings constantly change. It is a continuous process in which progeny with modification is produced.

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 3. The evolution occurring at a genetic level is called

1. Macroevolution
2. Mega evolutions
3. Inorganic evolution
4. Microevolution

Answer: 4. Microevolution

Microevolution is a series of changes within a species due to gene mutations and the accumulation of variations. It is an evolution occurring genetically.

Question 4. The term ‘evolution’ was coined by

1. Charles Darwin
2. Francesco Redi
3. Herbert spencer
4. Aristotle

Answer: 3. Herbert Spencer

The term evolution was given by Herbert Spencer

Biology MCQ For NEET With Answers

Question 5. Which of the following is the correct sequence of events in the origin of life?

1. Formation of protobionts
2. Synthesis of organic monomers
3. Synthesis of organic polymers
4. Formation of dna-based genetic systems

Choose the correct option

1. 1, 2, 3, 4
2. 1, 3, 2, 4
3. 2, 3, 1, 4
4. 2, 3, 4, 1

Answer: 3. 2, 3, 1, 4

The correct sequence of events in the origin of life is as follows

Synthesis of organic monomers
Synthesis of organic polymers
Formation of protobionts
Formation of DNA-based genetic systems.

“which one is not an example of analogous structures “

Question 6. Which of the following gas was absent in the atmosphere at the time of the origin of life?

1. NH3
2. H2
3. O2
4. Ch4

Answer: 3. O2

Primitive conditions on the earth were high temperatures, volcanic storms, and a reducing atmosphere containing CH4, NH3, H2, etc. There was no oxygen on the primitive earth

Question 7. Consider the following statements regarding the origin of life.

The earliest organisms that appeared on the earth were non-green and presumably anaerobes.
The first autotrophic organisms were the chemoautotrophs that never released oxygen.
Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 3. Both statements 1 and 2 are correct

The first originated organisms were prokaryotic chemoheterotrophs and oxygen was not available on earth at that time, so it must be anaerobic too. Even the first autotrophs were dependent on chemicals as oxygen was not released. Thus, they were non-green chemoautotrophs

Biology MCQ For NEET With Answers

Question 8. Evolution means mp

History of race
Development of race
History and development of race with variations
Progressive development of the race
Answer: 3. History and development of race with variations

Evolution simply means an orderly change from one condition to another. Evolution is a continuous process in which progeny or race with modifications or variations are produced.

Question 9. Origin of life took place in/on

Water
Air
Mountains
Land
Answer: 1. Water

Primitive life originated in the water bodies on the primitive earth from inanimate matter by chemical evolution through a series of chemical reactions about 4 billion years ago

Question 10. The sequence of origin of life could be

1. Organic materials → inorganic materials → non-colloidal aggregate → eobiont → cell
2. Inorganic materials → organic materials → colloidal aggregates → eobiont → cell
3. Inorganic materials → organic materials → eobiont → cell → colloidal aggregate
4. Inorganic materials → inorganic materials → eobiont → cell → colloidal aggregate

Answer: 2. Inorganic materials → organic materials → colloidal aggregates → eobiont → cell

The sequence of origin of life is as follows Free atom → inorganic materials → organic materials → colloidal aggregates → origin of coacervates like droplets (Eobionts) → prokaryotes (Single cell organism) → eukaryotes (Multicellular organism)

Question 11. The origin of life as a result of chemical evolution was properly explained by

1. Fox
2. Oparin
3. Watson
4. Haeckel
5. Mendel
6. Crick

Choose the correct option.

1. 1 and 2
2. 3 and 4
3. 5 and 6
4. Only 2

Answer: 4. Only 2

Oparin and Haldane explained the chemical evolution of life.

Biology MCQ For NEET With Answers

Question 12. According to one of the most widely accepted theories, earth’s atmosphere before the origin of life consisted of a mixture of

1. O3, CH4 , O2 and HO2
2. O2, NH3, CH4 and HO2
3. H2, CO2, NH3 and CH4
4. CH4, NH3, HO2 and HO2 vapours

Answer: 4. CH4, NH3 , H2 and HO2 vapours

According to one of the most widely accepted theories, the earth’s atmosphere before the origin of life consisted of a mixture of CH4, NH3, H2 and water vapours.

The atmosphere of primitive Earth was strongly reducing. At high temperatures (5000°C to 6000°C) elements like hydrogen, oxygen, carbon and nitrogen could not exist in a free state.

These combined variously either among themselves or with metals forming oxides, carbides and nitrides.

Question 13. The idea of the ‘fiery origin of the earth’ was given by

1. Lamaitre
2. James jeans
3. Haldane
4. Oparin

Answer: 2. James’ jeans

The idea of the fiery origin of the earth was given by James Jeans. According to the Tidal creation theory as proposed by James Jeans, a huge tide was caused by the sun’s surface by the gravitational pull of a stray star.

“neet ug biology class 12 genetics and evolution “

It was followed by a scattering of bits of the crest of a high wave into space resulting in the formation of planets. Thus, each planet, including Earth was a fiery chunk that cooled down over billions of years.

Question 14. Which of the following compounds has a very important role in pre-biotic evolution?

1. CH4
2. SO2
3. SO3
4. NO

Answer: 1. CH4

CH4 (methane) was probably the first organic compound formed on primitive earth, and thus has an important role in pre-biotic evolution.

\(\mathrm{CH}_4+2 \mathrm{O}_2 \rightarrow \mathrm{CO}_2+2 \mathrm{H}_2 \mathrm{O}\)

Biology MCQ For NEET With Answers

Question 15. The correct sequence for the manufacture of the gases on the primitive earth is

1. NH3, nucleic acid, protein and carbohydrate
2. Protein, carbohydrate, water and nucleic acid
3. NH3, protein, carbohydrate and nucleic acid
4. NH3, water, nucleic acid and protein

Answer: 4. NH3, water, nucleic acid and protein

The correct sequence for the manufacture of the gases on the primitive earth is NH3, water, nucleic acid and protein. There were abundant hydrogen atoms in the primitive atmosphere.

First H2 combined with nitrogen to form ammonia and later it combined with molecular O2 to form water.

Later, CH4 H2O and NH3, combined to form amino acids which got polymerised into proteins.

H2 -bases, sugars and phosphates combined to form nucleic acids.

Question 16. One of the possible early sources of energy was/was aims

1. CO2
2. Chlorophyll
3. Green plants
4. Uv-rays and lightening

Answer: 4. Uv-rays and lightening

“evolution questions “

In the primitive atmosphere, the external sources of energy were – solar radiations such as ultraviolet light, X-rays, etc. energy from electrical discharges like lightning

Question 17. The first organisms to evolve on the earth were

1. Saprotrophs
2. Photoautotrophs
3. Chemoautotrophs
4. Chemoheterotrophs

Answer: 3. Chemoautotrophs

Both statements 1 and 2 are correct. The first originated organisms were prokaryotic chemoheterotrophs and oxygen was not available on earth at that time, so it must be anaerobic too.

Even the first autotrophs were dependent on chemicals as oxygen was not released. Thus, they were non-green chemoautotrophs

Question 18. Origin of life is also called

1. Biogenesis
2. Protobiogenesis
3. Biopoiesis
4. All of these

Answer: 4. All of these

Biogenesis is the production of new living organisms or organelles. The origin of life on the earth is called proto-biogenesis.

Biopoiesis is a process by which living organisms are thought to develop from non-living matter. So, the origin of life is also called biogenesis, proto-biogenesis and biopoiesis

Biology MCQs with answers for NEET

Question 19. Which of these are considered most essential in the origin of life?

1. Enzymes
2. Nucleic acids
3. Carbohydrates
4. Proteins

Answer: 2. Nucleic acids

Nucleic acids are the polymer of nucleotides that exhibits the unique ability of self-replication and self-perpetuation.

Owing to their ability of self-replication, nucleic acids serve as genetic material and carriers of heredity traits from one generation to the next which is a pre-requisite for living organisms.

Thus, nucleic acids are the most essential in the origin of life

Question 20. The concept of evolution was given by Punjab

1. Darwin
2. Aristotle
3. Lamarck
4. Empedocles

Answer: 4. Empedocles

Empedocles, a philosopher of Greek descent, lived in Sicily in the 5th century BCE.

Empedocles developed a theory of evolution that consisted of natural elements being acted upon by natural forces to create the world that we know today.

Question 21. From the point of view of early chemical evolution that preceded the origin of life on Earth, the most important simple organic molecules formed were

1. Sugars and amino acids
2. Glycerol and fatty acids
3. Purines and pyrimidines
4. All of the above

Answer: 4. All of the above

The early inorganic molecules interacted and produced simple organic molecules such as simple sugars (e.g. ribose, deoxyribose, glucose, etc.), nitrogenous bases (e.g. purines, pyrimidines), amino acids, glycerol, fatty acid, etc.

Biology MCQs with answers for NEET

Question 22. The simple organic compounds that may have first evolved in the direction of the origin of life on Earth, may have been

1. Proteins and amino acids
2. Proteins and nucleic acids
3. Urea and nucleic acids
4. Urea and amino acids

Answer: 2. Proteins and nucleic acids

Proteins and nucleic acids were the first to evolve on Earth which was required for the origin of life. Protein originated before the nucleic acids. In the nucleic acids (RNA and DNA), RNA was the first genetic material

Question 23. Life cannot originate today because

1. Raw materials are not available
2. Life has already originated
3. Today’s atmosphere is reducing
4. Today’s atmosphere is oxidising

Answer: 4. Today’s atmosphere is oxidising

An atmosphere containing free oxygen would be fatal to all origins of life schemes. While oxygen is necessary for life, free oxygen would oxidise and thus, destroy all organic molecules required for the origin of life. Thus, life cannot originate in existing oxidising atmosphere conditions.

“evolution mcq “

Question 24. The source of energy at the time of the origin of life was

1. Volcanic eruptions, radioactive decay and lightning
2. Burning of fossil fuels
3. Cosmic rays only
4. Lightning only

Answer: 1. Volcanic eruptions, radioactive decay and lightning

New analysis shows that radioactive decay, lightning and gases from volcanic eruptions were the sources of energy at the time of origin and these could have given rise to the first life on earth

Biology MCQs with answers for NEET

Question 25. Which one of the following is the correct sequence of chemical substances produced during the origin of life on the earth?

1. Water, amino acid, nucleic acid and enzyme
2. Glucose, amino acid, nucleic acid and protein
3. Amino acid, ammonium phosphate and nucleic acid
4. Ammonia, amino acid, protein and nucleic acid

Answer: 1. Water, amino acid, nucleic acid and enzyme

Life was preceded by biomolecules. Biomolecules evolved from simple inorganic molecules present in the primitive atmosphere on Earth like methane, ammonia, hydrogen, nitrogen and water vapour.

These simple molecules combined under the influence of thunder lightning to generate amino acids.

Aggregates of amino acids later on produced nucleic acids and biological catalysts, i.e. enzymes. Thus, the correct sequence is water, amino acid, nucleic acid and enzyme.

Question 26. It is useful to study the origin and evolution of life because

1. It cannot exist anywhere else
2. We learn about unity and diversity
3. We learn that the human species has the responsibility to conserve nature
4. The human species is not the most evolved

Answer: 2. We learn about unity and diversity

The remarkably diverse forms of life on this planet arose from evolutionary processes. A striking unity underlies the diversity of life. For example, DNA is the universal genetic language common to all organisms.

Similarities between organisms are evident at all levels of the biological hierarchy.

Question 27. Which of the following statements does not explain the usefulness of the study of the origin and evolution of life?

1. We learn that life can exist anywhere else also
2. We learn about the unity and diversity of living organisms
3. The human species is the most evolved, so no harm can be done to us
4. We learn that human beings have the responsibility to conserve nature

Answer: 3. The human species is the most evolved, so no harm can be done to us

The statement in option 3 does not explain the usefulness of the study of the origin and evolution of life. It can be corrected as Evolution is a theory of change over the course of time.

Not only humans but many species are the most evolved. Rest all options are correct

Biology MCQs with answers for NEET

Question 28. An examination of fossils and other materials indicates that

1. Life has been in existence since the beginning of the earth
2. Life appears to have been in existence for more than three billion years
3. Life may not have existed on Earth until about two billion years ago
4. Life was transported on the earth from some other planets

Answer: 2. Life appears to have been in existence for more than three billion years

The oldest known fossils are around 3.5 billion years old, 14 times the age of the oldest dinosaurs.

But the fossil record may stretch back still further. For instance, in August 2016 researchers found what appear to be fossilised microbes dating back 3.7 billion years

Question 29. Galaxies of the present-day universe were formed due to condensation by …… Earth, situated in the milky way galaxy is said to have been formed about ……. Ago. Gases such as NH4, CO2, water vapour and……. Were released. Choose the correct options in order

1. Gravitation, 4.5 billion years, methane
2. Acceleration, 2.5 billion years, sulphur
3. Freezing, 1.5 billion years, ethane
4. Acceleration, 4.5 billion years, methane

Answer: 1. Gravitation, 4.5 billion years, methane

Question 30. How old is our universe?

1. 10 Billion years old
2. 20 Billion years old
3. 15 Billion years old
4. 200 Billion years old

Answer: 2. 20 Billion years old

The origin of life on Earth is estimated to have occurred around 3.5 billion or 3500 million years ago dusters of galaxies comprise the universe.

Question 31. The origin of life on earth dates back to hp

1. 6000 million years
2. 3500 million years
3. 2000 million years
4. 10,000 million years

Answer: 2. 3500 million years

The origin of life on earth is estimated to have occurred around 3.5 billion or 3500 million years ago

Question 32. After about how many years of the formation of the earth, life appeared on this planet?

1. 500 Billion years
2. 50 million years
3. 500 million years
4. 50 Billion years

Answer: 3. 500 Million years

Life appeared 500 million years after the formation of Earth, i.e. almost 4 billion years back.

Question 33. The long gap of 3500 million years between the origin of the earth and of life on it was due to a lack of

1. Oxygen
2. Water
3. Dna
4. Suitable temperature

Answer: 4. Suitable temperature

The earth is believed to be originated about 4500 million years ago (in the Precambrian Era).

Earlier earth’s surface was too hot (about 1000°C). At this temperature, life was not possible and water molecules existed in vapour form. It took a long time to cool down the earth.

About 3500 million years ago, the earth’s surface became cool enough to hold water and the large water bodies or the first ocean came into existence.

It marked the beginning of the first life on the earth and water was the most essential factor for the origin of life.

Thus, a long gap between the origin of earth and life was due to the lack of suitable temperature

NEET Biology Mcq

Question 34. The temperature in the interior of the sun is above 20000000°c, the reason for this high temperature is

1. Various exothermic reactions are taking place
2. Fusion converts the hydrogen of the sun to helium
3. Collision of particles releasing energy
4. None of the above

Answer: 2. Fusion converting hydrogen of the sun to helium

The temperature in the interior of the sun is about 20000000°C. The reason for this high temperature is fusion reactions that convert the hydrogen of the sun to helium

Question 35. The discovery of fossils of cyanobacteria indicates that life originated sometime

1. Prior to 4600 million years ago
2. Between 4600 and 3600 million years ago
3. Around 3600 million years ago
4. During some other period

Answer: 3. Around 3600 million years ago

Cyanobacteria (Cyanophyta) are a group of bacteria, previously known as blue-green algae.

They are unicellular and non-motile, often coated with mucilaginous slime and the photosynthetic membranes occur as thylakoids within the cell cytoplasm rather than being in a membrane-bounded chloroplast.

The cyanobacteria have an extensive fossil record.

Question 36. Anaerobic photosynthetic bacteria appeared on the Earth about

1. 500 million years ago
2. 1500 million years ago
3. 2500 million years ago
4. 3500 million years ago

Answer: 4. 3500 Million years ago

Evolution of life-3800-4200 million years back (mya). Evolution of bacteria 3500-3800 mya. Evolution of cyanobacteria 3300- 3500 mya. Evolution of eukaryotic algae 1600 mya.

Question 37. Who proposed the big-bang theory?

1. Father Suarez
2. Abbe lemaitre
3. Arno allen penzias
4. Edwin p hubble

Answer: 2. Abbe lemaitre

There are several theories regarding the origin of the universe, but the most accepted is the Big Bang theory.

It was proposed by Abbe Lemaitre in 1931. According to the Big Bang theory, about 15-20 billion years ago, cosmic matter was in a condensed form consisting of high-energy neutrons.

The explosion took place due to the movement of these neutrons which broke the condensed matter and scattered its fragments into space at an enormous velocity making a Big Bang sound and thus, the theory came to be known as the Big Bang theory.

Question 38. An attempt to explain the origin of ……………… Was made by big-bang theory.

1. Earth
2. Solar-system
3. Universe
4. Continents

Answer: 3. Universe

There are several theories regarding the origin of the universe, but the most accepted is the Big Bang theory.

It was proposed by Abbe Lemaitre in 1931. According to the Big Bang theory, about 15-20 billion years ago, cosmic matter was in a condensed form consisting of high-energy neutrons.

The explosion took place due to the movement of these neutrons which broke the condensed matter and scattered its fragments into space at an enormous velocity making a Big Bang sound and thus, the theory came to be known as the Big Bang theory.

NEET Biology Mcq

Question 39. Assertion According to the big-bang hypothesis, about 20 billion years ago the universe was a big ball of only neutrons. Reason (r) movement of these particles is known to generate tremendous heat which caused explosion due to temperature and pressure changes.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r is false
4. Both a and r are false

Answer: 1. Both a and r are true and r is the correct explanation of a

Both A and R are true and R is the correct explanation There are several theories regarding the origin of the universe, but the most accepted is the Big Bang theory.

It was proposed by Abbe Lemaitre in 1931. According to the Big Bang theory, about 15-20 billion years ago, cosmic matter was in a condensed form consisting of high-energy neutrons.

The explosion took place due to the movement of these neutrons which broke the condensed matter and scattered its fragments into space at an enormous velocity making a Big Bang sound and thus, the theory came to be known as the Big Bang theory.

Question 40. Assertion big-bang theory is based on studies of sir james jeans. Reason (r) he gave the theory of steady state.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r is false
4. Both a and r are false

Answer: 3. A is true, but r is false

A is true, but R is false and Reason can be corrected as In cosmology, the steady-state model is an alternative to the Big Bang theory of the evolution of the universe.

The steady-state model was proposed by three individuals in 1948, Hermann Bondi, Thomas Gold and Fred Hoyle

Question 41. According to scientists, the big bang occurred approximately ………………….. Years ago.

1. 100 Million-200 million
2. 100 Thousand
3. 1 Billion
4. 15-20 Billion

Answer: 4. 15-20 Billion

According to scientists, the Big Bang occurred about 15-20 billion years ago.

NEET Biology Mcq

Question 42. According to the theory of special creation

1. All the living beings on earth were created by god or supernatural power
2. All the living beings on earth were in the form of spores or microorganisms
3. All the living beings on earth originated from non-living material
4. All living beings originated from pre-existing living forms

Answer: 1. All the living beings on earth were created by god or supernatural power

The theory of special creation states that life was created by God or supernatural power, in the same conditions as they exist now.

Question 43. The theory of special creation was given by

1. Weismann
2. Helmont
3. Maupertuis
4. Father Suarez

Answer: 4. Father Suarez

Father Suarez was a strong believer (supporter) of the theory of special creation. He believed that the whole life on earth was formed in 6 days.

Question 44. The theory of special creation argues that

1. All living organisms were created as they are in present times.
2. Diversity was always the same since creation.
3. Earth is 4000 years old.

Choose the right option to complete the given statement.

1. 1 and 2
2. 2 and 3
3. 1 and 3
4. 1, 2 and 3

Answer: 4. All statements are correct.

The greatest supporter of the special creation theory was Father Suarez.

According to this theory, life was created by supernatural powers and the world was created in six days.

The earth is 4000 years old. All the diversity has existed since creation.

Question 45. The cosmozoic theory was given by

1. Darwin
2. Richter
3. Aristotle
4. Van Baer

Answer: 2. Richter

Cosmozoic theory or the theory of panspermia was proposed by Richter in 1865 and was later supported by Arrhenius in 1908.

NEET Biology Mcq

Question 46. The extra-terrestrial origin of life was proposed by

1. Natural selection
2. Origin of species
3. Continental drift
4. Theory of panspermia

Answer: 4. Theory of panspermia

The theory of panspermia was proposed by Richter. According to this theory, protoplasm reached Earth in the form of spores or germs from unknown or extra-terrestrial parts of the universe with cosmic dust and subsequently evolved into various forms of life.

Question 47. Assertion Arrhenius considered panspermia as mainly responsible for the transfer of germs from other planets to Earth.  Reason (r) present-day study of meteorites like allan hill: 84001 which was knocked out from Mars in Antarctica, is rich in aromatic hydrocarbons deposited by biological activity.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r is false
4. Both a and r are false

Answer: 2. Both a and r are true, but r is not the correct explanation of a

Both A and R are true, but R is not the correct explanation of A. Arrhenius considered panspermia as mainly responsible for the transfer of germs from other planets to Earth.

The cosmozoic or interplanetary theory was put forward by Richter and supported by Arrhenius and others.

It stated that life had reached the earth from some other heavenly body in the form of resistant spores.

Present day study of a meteorite called Allan Hills 84001 which was knocked out from Mars in Antarctica revealed that it is rich in aromatic hydrocarbons deposited by biological activity.

Microscopic fossils of bacteria in the meteorite suggested that these organisms originated on Mars, but these claims are controversial

Question 48. Who disapproved of the theory of spontaneous generation?

1. Urey and miller
2. Oparin
3. Redi, spallanzani and pasteur
4. Aristotle

Answer: 3. Redi, spallanzani and pasteur

The theory of spontaneous generation is also called abiogenesis or autogenesis. This theory states that life originated from non-living by itself or
spontaneous manner.

Francesco Redi, Louis Pasteur and Spallanzani disapproved of the theory of abiogenesis

NEET Biology Mcq

Question 49. Louis Pasteur is famous for

1. Recapitulation theory
2. The germ theory of diseases
3. Cell theory
4. Both 1 and 3

Answer: 2. Germ theory of diseases

The germ theory of disease is the currently accepted scientific theory for many diseases.

The more formal experiments on the relationship between germ and disease were conducted by Louis Pasteur between the years 1860 and 1864

Question 50. Which one of the following experiments suggested that the simplest living organisms could not have originated spontaneously from non-living matter?

1. Microbes did not appear in stored meat
2. Larvae could appear in decaying organic matter
3. Microbes appeared from unsterilised organic matter
4. The meat was not spoiled when heated and kept sealed in a vessel

Answer: 4. Meat was not spoiled when heated and kept sealed in a vessel

Francesco Redi, an Italian physician, took the flesh and cooked it so that no organisms were left alive.

Then he placed flesh in three jars, of which, one was uncovered, the second was covered with parchment and the third one was covered with fine muslin.

He kept these jars for a few days and observed that maggots developed only in the uncovered jar though the flies also visited other jars.

Thus, an experiment in option (d) suggested that the simplest living organisms could not have originated spontaneously from non-living matter

Question 51. The theory of spontaneous generation or abiogenesis was disproved by swan flask experiments by

1. Ar Wallace
2. Francesco redi
3. Louis pasteur
4. Ai oparin
5. Sidney fox

Answer: 3. Louis pasteur

Louis Pasteur conducted an experiment with a swan-necked flask to discredit the theory of spontaneous generation. The infusion was boiled till the steam rushed out of the neck of the flask.

Microorganisms did not develop when the flask was left open. When its neck was broken, bacteria appeared immediately.

Question 52. Louis Pasteur’s view on the origin of life is that

1. Life originated within six days
2. Life originated from the living organisms
3. Only life originated spontaneously from the non-living substances
4. Life came from other planets

Answer: 2. Only life originated spontaneously from the non-living substances

Louis Pasteur carefully experimentally demonstrated that, life comes only from pre-existing life.

He showed that in pre-sterilised flasks life did not come from killed yeast, while in another flask open to the air, new living organisms arose from ‘killed yeast

Question 53. Van Helmont believed that mice originate from wheat grains and dirty clothes. He, therefore, favoured the theory of

1. Biogenesis
2. Spontaneous generation
3. Pangenesis
4. Cosmozoic

Answer: 2. Spontaneous generation

Abiogenesis is the spontaneous generation theory, according to which fully formed living organisms sometimes arise from non-living matter.

The theory of abiogenesis or spontaneous generation was based on ancient superstition rather than any scientific research.

This theory was believed and supported by Thales, Anaximander, Newton, Descartes and van Helmont. van Helmont described that mice arise from the wheat barns and sweaty shirts kept in a pot for 21 days in the dark

NEET Biology Mcq

Question 54. To disprove the theory of the spontaneous origin of life, the nutritious broth in glass flasks was boiled and sealed. The bottle remained clear and sterile. Who was the first to perform such an experiment?

1. Pasteur
2. Lazzaro spallanzani
3. Oparin
4. Francesco redi

Answer: 2. Lazzaro spallanzani

Spallanzani disapproved of the theory of abiogenesis (spontaneous generation).

He experimented with animal and vegetable broths and boiled them for several hours. He soon after sealed them to ensure the broths were never infested with microorganisms.

From this experiment, he concluded that high temperatures had killed all living organisms in the broths and without them, life did not appear. When the broths were left exposed to air, it was soon invaded by microorganisms

Question 55. The accepted theory of the origin of life is

1. Spontaneous generation theory
2. Self-assembly theory
3. Biogenesis theory
4. Cosmozoic theory

Answer: 3. Biogenesis theory

The most accepted theory of the origin of life today is the biogenesis theory

Question 56. The term ‘proto biogenesis’ is used for the theory of

1. Biochemical origin of life
2. Panspermia
3. Spontaneous generation
4. Special creation

Answer: 1. Biochemical origin of life

The term proto-biogenesis is used for the theory of the biochemical origin of life. Protobiogenesis refers to the origin of the first life form non-living chemical assemblages.

Question 57. According to abiogenesis, life originates from

1. Non-living
2. Other planes
3. Pre-existing life
4. Spontaneously

Answer: 1. Non-living

Abiogenesis states that life originated from non-living things in a spontaneous manner

Question 58. The idea that life originates from pre-existing life is referred as

1. Biogenesis theory
2. Special creation theory
3. Abiogenesis theory
4. Extra-terrestrial theory

Answer: 1. Biogenesis theory

Biogenesis theory states that life originates only from pre-existing life

Question 59. The abiogenesis occurred about how many billion years ago?

1. 1.2 billion
2. 1.5 billion
3. 2.5 billion
4. 3.5 billion

Answer: 4. 3.5 billion

Abiogenesis was supposed to occur about 3.5 billion years ago

Question 60. Select the wrong pair.

1. Haldane -hot dilute soup
2. Oparin -protobiont
3. Fox -coacervates
4. Spallanzani -approved abiogenesis
5. Francesco redi -biogenesis

Answer: 4. Francesco redi -biogenesis

Option 4 is the wrong pair and it can be corrected as Spallanzani disapproved abiogenesis and approved biogenesis. The rest of other options are correctly matched pair.

Question 61. With reference to the origin of life, Aristotle believed in

1. Cosmozoic theory
2. Special creation
3. Abiogenesis
4. Panspermia

Answer: 3. Abiogenesis

Aristotle developed his Scala Naturae, or Ladder of Life, to explain his concept of the advancement of living things from inanimate matter to plants, then animals and finally man. He supported the theory of spontaneous generation (abiogenesis or autogenesis).

Question 62. The concept of chemical evolution is based on

1. Interaction of water, air and clay under intense heat
2. Effect of solar radiation on chemicals
3. Possible origin of life by a combination of chemicals under suitable environmental conditions
4. Crystallisation of chemicals

Answer: 3. Possible origin of life by a combination of chemicals under suitable environmental conditions

The concept of chemical evolution is based on the possible origin of life by a combination of chemicals under suitable environmental conditions.

The distribution of elements in the cosmos is the result of many processes in the history of the universe.

It provides a powerful tool to study the Big Bang, the density of baryonic matter, nucleosynthesis and the formation and evolution of stars and galaxies.

Question 63. The theory of the origin of life as a result of chemical evolution has been properly explained by

1. Stanley miller
2. Darwin
3. Oparin
4. S fox

Answer: 3. Oparin

Oparin (1894-1980) was a Russian scientist. He published his book ‘The Origin of Life in 1936.’ In his book, he mentioned that the origin of life takes place as a result of chemical evolution

Question 64. Oparin and Haldane’s theory is also known as

1. The modern theory of the origin of life
2. Chemical theory of the origin of life
3. Naturalistic theory
4. All of the above

Answer: 4. All of the above

The theory of chemical evolution is also called the modern theory of evolution or naturalistic theory of evolution.

Oparin and Haldane proposed that the first form of life could have come from pre-existing non-living organic molecules (e.g. RNA, protein, etc.) and that the formation of life was preceded by chemical evolution, i.e. formation of diverse organic molecules from inorganic constituents.

Question 65. In the Oparin theory, the most important/ essential element was

1. Proteins Jharkhand
2. Oxygen
3. Amino acids
4. Nitrogen, ammonia and methane

Answer: 3. Amino acids

The Oparin-Haldane hypothesis suggested that life arose gradually from inorganic molecules, with building blocks like amino acids forming first and then, they combined to make complex polymers.

Thus, amino acids were the most essential element in Oparin theory.

Question 66. Oparin and Haldane proposed

1. The theory of natural selection
2. That migration affects the genetic equilibrium
3. That mutation caused speciation
4. That the first form of life could have come from pre-existing non-living organic molecules
5. That evolution of life forms had been driven by the use and disuse of organs

Answer: 4. That evolution of life forms had been driven by the use and disuse of organs

According to Oparin-Haldane’s theory of the origin of life, ‘life’ originated on earth spontaneously from preexisting non-living organic molecules.

First inorganic compounds and then organic compounds were formed in accordance with ever-changing environmental conditions.

This is called chemical evolution which cannot occur under present environmental conditions on Earth.

Question 67. Abiogenic organic matter of sea at the time of origin of life was called ‘hot dilute soup’ by

1. M calvin
2. Sl miller
3. F redi
4. Jbs haldane

Answer: 4. Jbs haldane

JBS Haldane described the sea containing biomolecules like monosaccharides, amino acids, purines, pyrimidines, fatty acids and glycerol in abundance as the hot dilute soup or primitive broth. The hot dilute soup was without oxygen.

Question 68. According to the abiogenic origin of life proposed by Oparin, …………… Was the simplest organic compound to arise.

1. Organic acids
2. Hydrocarbons
3. Carbohydrates
4. Proteins.

Answer: 2. Hydrocarbons

In 1924, Oparin officially put forward his influential theory that life on earth developed through the gradual chemical evolution of carbon-based molecules called hydrocarbons, which was the simplest organic compound in a primordial soup.

Question 69. The possible details of the chemical evolution of the most elementary forms of life were particularly well-worked out experimentally by

1. Haldane
2. sydney w fox
3. Urey and miller
4. Ai pain

Answer: 3. Urey and Miller

Experimentally, the chemical theory of evolution was proved by SL Miller
and HC Urey in 1953.

They performed electric experiments and observed the formation of sugar, nitrogen bases, pigment and fats

Question 70. To determine which molecules might have formed spontaneously on early Earth, Stanley Miller used an apparatus with an atmosphere containing

1. Oxygen, hydrogen and nitrogen
2. Oxygen, hydrogen, ammonia and water vapour
3. Oxygen, hydrogen and methane
4. Hydrogen, ammonia, methane and water vapour

Answer: In his experiment, Miller used a mixture of methane, ammonia, hydrogen and water. The mixture was exposed to electric discharges, followed by condensation and then boiling.

He analysed the chemical composition of the liquid inside the apparatus and found a large number of simple organic compounds including some amino acids. Miller proved that organic compounds were the basis of life.

Question 71. Formation of which complex molecules was noticed by Urey and Miller when they subjected substances like NH3, CH4 and HO2 to electric discharge?

1. H2SO3
2. Amino acids
3. Hydroponics
4. HCN

Answer: 2. Amino acids

Experimentally, the chemical theory of evolution was performed by SL Miller and HC Urey in 1953. They created electric discharge in a closed flask containing water vapour at 800 °C and observed the formation of amino acids

Question 72. Which of the following statements about Miller and Urey’s experiment
is correct?

1. The gases used were only methane (CH4 ) and ammonia (NH3)
2. A continuous magnetic wave was passed through the system, to simulate lightning storms believed to be common on the early earth
3. Experiments showed that organic compounds such as amino acids, could not be made easily under the conditions believed to be present on the early earth
4. None of the above

Answer: 4. None of the above

All statements are incorrect about Miller and Urey’s experiment. In Stanley L Miller and Harold C Urey’s experiment, the gases used were methane (CH4 ), ammonia (NH3), hydrogen (H2) and water (HO2 ).

Next, a continuous electric current was passed through the system, to simulate lightning storms that were believed to be common on the early earth.

This experiment showed that organic compounds such as amino acids, which are essential to cellular life, could be made easily under the conditions that were believed to be present on the early earth.

Question 73. What did Miller observe after the completion of his experiment?

1. Amino acids
2. Organic compounds
3. Peptides
4. All of the above

Answer: 4. All of the above

Miller circulated four gases methane, ammonia, hydrogen and water vapour in an air-tight apparatus and passed electrical discharges from electrodes at 800°C.

After a week, he found a large number of simple organic compounds including amino acids such as alanine, glycine, aspartic acid and small peptides.

Other substances such as urea, hydrogen cyanide, lactic acid and acetic acid were also present.

Question 74. The ratio of methane, ammonia and hydrogen in Stanley Miller’s experiment was

1. 3: 1: 2
2. 2: 1: 2
3. 1 : 2: 1
4. 5: 4: 1

Answer: 2. 2: 1: 2

The ratio of methane, ammonia and hydrogen in Miller’s experiment was 2: 1: 2.

Question 75. The given diagram represents Miller’s experiment. Choose the correct combination of labelling for a, b, c, d and e.

1. A–electrodes, B–NH4+ H2 + HO2 + CH4, C–cold water, D–vacuum, E–u-trap
2. A–electrodes, B–NH4 + H2 + co2 + ch 3, C–hot water, D–vacuum, E–u-trap
3. A–electrodes, B–NH HO3 2+ + CH4 c–steam, d–vacuum, E–u-trap
4. A–electrodes, B–NH h3 2+ +HO2 + ch4, c–hot steam, D–vacuum, E–u-trap
5. A–electrodes, B–NH3 + CH4, C–cold water, D–sink, E–u-trap

Answer: 1. A–electrodes, B–NH4+ H2 + HO2 + CH4, C–cold water, D–vacuum, E–u-trap

Question 76. Which one of the following amino acids was not found to be synthesised in Miller’s experiment?

1. Aspartic acid
2. Glutamic acid
3. Alanine
4. Glycine

Answer: 2. Glutamic acid

Glutamic acid is one of the non-essential amino acids, closely related to glutamine.

It was not synthesised in Miller’s experiment. It is an important metabolic intermediate as well as a neurotransmitter molecule in the central nervous system.

Question 77. In Miller’s experiment, he used a mixture of ch nh h 4 3 2, and water vapour in a closed flask to mimic early earth conditions. What was the temperature at which this flask was kept?

1. 800°C
2. 1200°C
3. 200°C
4. 400°C

Answer: 1. 800°C

The primitive earth had a high temperature. Therefore Miller kept the mixture in the flask at 800°C to mimic early earth conditions.

Question 78. Coacervates were experimentally produced by,

1. Sydney Fox and pain
2. Fischer and Huxley
3. Jacob and Monod
4. Urey and miller

Answer: 1. Sydney Fox and pain

Oparin and Sydney Fox stated that large organic molecules synthesised abiotically on primitive earth later came together spontaneously and due to intermolecular attraction, formed large colloidal aggregates called coacervates.

Question 79. Which of the following is said to have first evolved on primitive Earth?

1. Viroids
2. Coacervates
3. Cyanobacteria
4. Mycoplasma

Answer: 2. Coacervates

The large organic molecules, which were synthesised abiotically on the primitive earth later came together due to intermolecular attraction and they formed large colloidal aggregates.

Such water-bound aggregates have been named microspheres by Sydney Fox. Later these colloidal bodies were named coacervates by Oparin.

Question 80. Assertion coacervates are believed to be the precursors of life. Reason (r) coacervates are self-duplicating aggregates of proteins surrounded by a lipid bilayer.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r is false
4. Both a and r are false

Answer: 3. A is true, but r is false

Coacervates and microspheres are believed to be the precursors of life. The coacervates mainly contain proteins, polysaccharides and some water. Coacervates do not have a lipid bilayer

Question 81. Some complex inorganic and organic compounds in hot sea aggregated in different combinations to form

1. Protoplasm
2. Pre-cell
3. Post cell
4. Coacervates

Answer: 4. Coacervates

Some complex inorganic and organic compounds in the hot sea were aggregated in different combinations to form coacervates. The term coacervates was given by IA Oparin.

According to him, coacervates are probiotics that are mainly made up
of aggregates of macromolecules (like lipids, carbohydrates, nucleic acids and proteins).

These aggregates remain surrounded by a layer of water which acts as a barrier.

Question 82. Which of the following molecules falls under the category of eobionts?

1. Coacervates
2. Microspheres

Choose the right option

1. Only 1
2. Only 2
3. 1 and 2
4. None of these

Answer: 3. 1 and 2

Eobionts are of two types Coacervates lack membranes, but exhibit some life-like characteristics. They are able to grow and divide.

Microsphere is a non-living collection of organic molecules with double-layered outer boundaries. The term was given by Sydney Fox (1958-1964). So, option 3 is correct

Question 83. Which one of the following is incorrect about the characteristics of protobionts (coacervates and microspheres) as envisaged in the biogenic origin of life?

1. They were able to reproduce
2. They could separate combinations of molecules from the surroundings
3. They were partially isolated from the surroundings
4. They could maintain an internal environment

Answer: 2. They could separate combinations of molecules from the surroundings

A protobiont is an aggregate of abiotically produced organic molecules surrounded by a membrane.

Protobionts exhibit some of the properties associated with life including simple reproduction, metabolism and excitability as well as the maintenance of an internal chemical environment different from that of their surrounding.

They were partially isolated from the environment, but they could not separate combinations of molecules from the surroundings

Question 84. Coacervates are

1. Protobionts having polysaccharide + protein + HO2
2. Protein aggregate
3. Protein and lipid aggregates
4. None of the above

Answer: 1. Protobionts having polysaccharide + protein +HO2

The coacervates are a mixture of large proteins and polysaccharides and some water.

Question 85. Coacervates were formed by

1. Radiations
2. Polymerisation
3. Polymerisation and aggregation
4. Dna

Answer: 3. Polymerisation and aggregation

The coacervates are a mixture of large proteins and polysaccharides and some water. The coacervates were formed by polymerisation and aggregation of proteins.

Question 86. An evolving coacervate-like system would have needed a controlled and constant source of energy for

1. Making large complex molecules
2. Organising these molecules into structural patterns
3. Maintaining their organisation
4. All of the above

Answer: 4. All of the above

Coacervates require a controlled and constant source of energy for making complex molecules, organising these molecules into structural patterns and maintaining the organisation of these molecules.

Question 87. What is/are true about microspheres?

1. These are small spherical aggregates of proteinoids
2. These are considerably stable
3. These have a double-layered boundary, corresponding to the cell membrane
4. All of the above

Answer: 4. All of the above

Microspheres are small spherical aggregates of proteinoids. These are considerably stable due to the presence of double layered membrane around them.

Question 88. The heterotroph hypothesis assumes that

1. A simple organism originated in complex surroundings
2. A complex organism originated in simple surroundings
3. Life came from some other planet
4. Life was created by special creation

Answer: 2. A complex organism originated in simple surroundings

The heterotroph hypothesis assumes that complex evolved slowly from simple non-living matter and this occurred in primitive environmental conditions.

Question 89. The first life that appeared in marine water was called provirus, eobiont or protocell. It was

1. Anaerobic and chemoheterotrophic
2. Aerobic and parasitic
3. Chemoheterotrophic and aerobic
4. Anaerobic and autotrophic

Answer: 1. Anaerobic and chemoheterotrophic

The first cells evolved about 3900-4000 million years ago in the sea. The atmosphere was anaerobic at that time. Protocells collected more substances and formed cytoplasm.

They became the first living beings. They were prokaryotes and chemoheterotrophs.

Question 90. The reducing environment of the primitive earth was transformed into an oxidising environment by

1. Photoautotrophs
2. Chemoautotrophs
3. Chemoheterotrophs
4. None of the above

Answer: 1. Photoautotrophs

Early earth’s atmosphere was reducing atmosphere. It contained actively reducing gases such as hydrogen, carbon monoxide and hydrogen sulphide. There was no oxygen in the atmosphere.

As chemical energy gradually reduced, this was proven to be a positive environment for photoautotrophs like cyanobacteria to evolve the photosynthetic metabolic pathways using sunlight as an energy source.

Due to photosynthesis by cyanobacteria, there was a gradual increase in the oxygen level of the earth’s atmosphere. This changed a reducing atmosphere to an oxidising atmosphere. Thus, option 1 is correct.

Question 91. The first formed organism (ribo-organism) used only ………………… For catalysing reactions.

1. Dna
2. Amino acids
3. Fatty acids
4. RNA

Answer: 4. RNA

Amino acids and fatty acids do not have catalytic properties and hence, options 2 and 3 are incorrect.

Nucleic acids were also formed in a primitive hot soup of the sea. RNA and DNA are the two types of nucleic acid out of which, we know RNA have catalytic properties. Thus, RNA served as enzymes in first life forms.

Question 92. Most biologists think that RNA was the first genetic material because

1. Amino acids were produced in Stanley Miller’s apparatus
2. Dna is the universal genetic material of eukaryotes
3. The existence of ribozymes suggests RNA was used to catalyse chemical reactions
4. Rna is simpler than dna

Answer: 3. Existence of ribozymes suggests RNA was used to catalyse chemical reactions

Most biologists think that RNA was the first genetic material. This is because rRNA in present-day organisms serves as a catalyst in peptide bond formation during protein synthesis.

The presence of ribozymes (RNA molecules that serve as enzymes) and sequence homology in prokaryotes and eukaryotic rRNA confirm the evolution of their catalytic function earlier during evolution.

Question 93. Biologists believe that the current dna → rna → protein system is the result of evolution because

1. The steps of ‘DNA → RNA → protein’ consists of many steps
2. Dna replication is complicated, but relatively error-free
3. Evidence indicates that RNA preceded dna as the genetic material
4. All of the above

Answer: 3. Evidence indicates that RNA preceded dna as the genetic material

Biologists believe that the current DNA → RNA → protein system is the result of a long period of evolution because evidence indicates that RNA preceded DNA as the genetic material

NEET Biology Molecular Basis Of Inheritance

Question 1. Broad-spectrum antibiotics like streptomycin bind to smaller subunits of ribosomes of prokaryotes, thereby

1. Inhibiting protein synthesis
2. Blocking the action of peptidyl transferase
3. Misleading of genetic code
4. Causing point mutation

Answer: 1. Inhibiting protein synthesis

Streptomycin is a broad-spectrum antibiotic that acts as an inhibitor of protein synthesis.

Question 2. Synthesis of DNA can be stopped by incorporating artificial

1. Ddatp
2. Ddgtp
3. Ddctp
4. All of these

Answer: 4. All of these

Dideoxynucleotides like dd ATP, ddGTP, ddCTP, etc., lack the 3′ — OH group. They would stop DNA synthesis because the 3′–OH group is required for the functioning of the DNA polymerase enzyme.

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 3. Which of the following is the correct sequence of units of genetics arranged in descending order of size?

1. Gene → cistron → muton → recon
2. Gene → muton → cistron → recon
3. Gene → recon → cistron → muton
4. Gene → cistron → recon → muton

Answer: 4. Gene → cistron → recon → muton

Studies have proved that a gene is not a unit of either function recombination or mutation. Benzer in view of his work, coined the terms cistron (unit of function), recon (unit of recombination), and muton (unit of mutation).

” molecular basis of inheritance”

Recon consists of one, two, or more nucleotide pairs. Muton consists of a single nucleotide pair. Cistron, on the other hand, is the length of DNA that codes for a specific polypeptide chain or a functional RNA molecule.

It may be several base pairs long. On arranging these in descending order of their size, a distinct hierarchy is developed with the gene at the top, muton at the base, and cistron and recon in between. Thus, the correct sequence is genes, cistron, recon, and muton.

Question 4. Nucleotide sequence changes in DNA are not passed to offspring in

1. Egg and sperm cells
2. Non-sexual cells
3. Diploid and haploid cells
4. All of the above

Answer: 4. All of the above

If the mutation or change in nucleotide sequences does not occur in the germ cells or if the mutation occurs in a non-sexual cell, then it will not pass on to the next generation. The non-germinal mutations are also called somatic mutations

Question 5. Below is a list of a few processes.

1. Transcription (eukaryotic)
2. Transcription (prokaryotic)
3. Replication (eukaryotic)
4. Translation (prokaryotic)
5. Translation (eukaryotic)

Choose the correct site of occurrence of the processes

1. 1–Nucleus, 2–cytoplasm, 3–nucleus, 4–cytoplasm, 5–cytoplasm
2. 1–Nucleus, 2–nucleus, 3– cytoplasm, 4–cytoplasm, 5–cytoplasm
3. 1–Cytoplasm, 2–cytoplasm, 3–nucleus, 4–cytoplasm, 5–nucleus
4. 1–Nucleus, 2–cytoplasm, 3–nucleus, 4–cytoplasm, 5–cytoplasm

Answer: 1. 1–Nucleus, 2–cytoplasm, 3–nucleus, 4–cytoplasm, 5–cytoplasm

“molecular biology mcq “

As there is no defined nucleus in prokaryotes, all three process (replication, transcription, and translation) takes place in their cytoplasm. In eukaryotes, transcription and replication occur in the nucleus, but translation occurs in the cytoplasm. Thus, option 1 is correct.

Question 6. Mitochondrial DNA is advantageous for evolutionary studies as

1. It is inherited only through the female parent and thus evolves in a way that allows the trees of relationships to be easily constructed
2. It is present in the X-chromosome
3. It first appeared in humans and is not found in other animals
4. It has evolved very fast

Answer: 1. It is inherited only through the female parent and thus evolves in a way that allows the trees of relationships to be easily constructed.

Mitochondrial DNA is advantageous for evolutionary studies because it is inherited only through the female parent and thus, evolves in a way that allows trees of relationship to be easily constructed.

Mitochondrial DNA is contributed by ova at the time of fertilization.

Question 7. The genome of Caenorhabditis elegans consists of

1. 3 Billion base pairs and 30,000 genes
2. 180 Million base pairs and 13,000 genes
3. 4.7 million base pairs and 4000 genes
4. 97 Million base pairs and 18,000 genes
5. 12 Million base pairs and 6000 genes

Answer: 4. 97 Million base pairs and 18,000 genes

Caenorhabditis elegans is a species of soil-dwelling nematode (roundworm) used as a model organism in molecular genetics and developmental biology.

The C. elegans genome is about 97 million base pairs long and consists of six chromosomes and a mitochondrial genome. The genome contains an estimated 18,000 protein-coding genes.

“molecular basis of inheritance pyq neet “

Question 8. How many times, DNA can replicate in the life of a cell?

1. Only once
2. Twice
3. Several times
4. Depends on the ploidy level

Answer: 1. Only once

The preparation for DNA replication initiation is tightly linked to cell cycle progression, ensuring that replication occurs only once per cycle.

Question 9. A mechanism that can cause a gene to move from one linkage group to another is

1. Translocation
2. Inversion
3. Crossing over
4. Duplication

Answer: 1. Translocation

Translocation refers to a change in the location of genes from one linkage group to another. It is the separation of a chromosome segment and its union with a non-homologous chromosome.

“which one of the following is not applicable to rna “

Question 10. Read the following four statements.

1. In transcription, adenosine pairs with uracil.
2. Regulation of lac operon by a repressor is referred to as positive regulation.
3. The human genome has approximately 50,000 genes.
4. Haemophilia is a sex-linked recessive disease.

How many of the above statements are right?

1. Two
2. Three
3. Four
4. One

Answer: 1. Two

In the given statements, only two statements are correct. Statements I and IV are correct, but statements 2 and 3 are incorrect.

Incorrect statements can be corrected In the presence of an inducer, such as lactose or allolactose, the repressor is inactivated by interaction with the inducer.

This allows RNA polymerase to access the promoter and transcription proceeds. Hence, regulation of lac operon by repressor is referred to as negative regulation.

The human genome is said to have approximately 3 × 109 bp and approximately 20,000-25,000 genes

Question 11. The compound rifampicin is very

1. Potent inhibitors of bacterial RNA polymerases
2. Potent inhibitors of bacterial DNA polymerases
3. Weak inhibitors of bacterial RNA polymerases
4. Weak inhibitors of bacterial DNA polymerases

Answer: 1. Potent inhibitors of bacterial RNA polymerases

“which of the following is an initiation codon “

Rifampicin is an effective antibiotic against tuberculosis. It can inhibit bacterial RNA polymerase and thus halts protein synthesis at the transcription level

Question 12. Which of the following has a thymine base in its composition?

1. Nodoc
2. Codon
3. Anticodon
4. Codogene

Answer: 4. Codogene

Codogene is the smallest possible sequence (triplet) of nucleotides present on the DNA strand which can specify one particular amino acid. Thus, cologne has thymine, whereas no-doc, codon, and anticodon have uracil, adenine, and guanine.

“bank of biology class 12 molecular basis of inheritance “

Question 13. The antibiotic not associated with the inhibition of protein synthesis is

1. Chloromycetin
2. Tetracycline
3. Puromycin
4. Penicillin

Answer: 4. Penicillin

All the listed broad-spectrum antibiotics except penicillin inhibit protein synthesis.

Question 13. Assertion of the expression of cellular genetic information is unidirectional. Reason (r) cancer virus goes topsy-turvy, therefore reverse transcription allows a sequence of RNA to be retrieved and used as genetic information.

1. Both a and r are true and r is the correct explanation of a
2. Both a and r are true, but r is not the correct explanation of a
3. A is true, but r false
4. Both a and r are false

Answer: 1. Both A and R are true and r is the correct explanation of a

“class 12th biology molecular basis of inheritance “

Question 14. Telomerase is an enzyme that is a

1. Simple protein
2. RNA
3. Ribonucleoprotein
4. Repetitive DNA

Answer: 3. Ribonucleoprotein

Telomerase is a ribonucleoprotein that adds specific DNA sequence repeats (TAG in all vertebrates) to the 3′ (three prime) end of DNA strands in the telomere regions.

The enzyme is a reverse transcriptase that carries its own RNA molecule, which is used as a template when it elongates telomeres, which are shortened after each replication cycle.

Biology MCQ For NEET With Answers Human Genome Project

Question 1. The human genome project was launched in

1. 1986
2. 1990
3. 1996
4. 1998

Answer: 2. 1990

In 1990, the US Department of Energy and the National Institute of Health embarked on and coordinated the project of sequencing the human genome called HGP or Human Genome Project.

Question 2. Genomics is

1. Study of chromosomes
2. Study of proteins
3. Study of genes and genomes
4. Study of body cells

Answer: 3. Study of genes and genomes

Genomics is an interdisciplinary field of biology focusing on the structure, function, evolution, mapping, and editing of genomes.

A genome is an organism’s complete set of DNA, including all of its genes. So, genomics is the study of genes and genomes.

transcription mcq

Question 3. It took ………….years to study the human genome project entirely and it was completed in ……….

1. 12, 2013
2. 13, 2003
3. 10, 2000
4. 3, 1993

Answer: The human genome project was completed in 13 years in 2003.

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 4. As per the human genome project, the exact number of nucleotides contained in the human genome is

1. 3164.7 million
2. 3163.7 million
3. 3162.7 million
4. 3160.7 million

Answer: 1. 3164.7 million

The human genome contains 3164.7 million nucleotide bases.

Question 5. Consider the following statements.

1. The average gene contains 350 bases.
2. The largest known human gene is dystrophin.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 2. Statement 1 is incorrect, but 2 is correct

The incorrect statement can be corrected as The average gene consists of 3000 bases and the largest known human gene being is dystrophin containing 2.4 million bases.

transcription mcq

Question 6. The number of functional genes in humans is around

1. 5,00,00,000
2. 3,00,000
3. 25,000
4. 30

Answer: 3. 25,000

There are an estimated 20,000-25,000 protein-coding or functional genes in humans.

Question 7. The human genome consists of approximately

1. 3 × 103 Base pairs
2. 3 × 109 Base pairs
3. 2000 Base pairs
4. 30,000 Base pairs

Answer: 2. 3 × 109 Base pairs

The human genome has approximately 3 × 109 base pairs.

Human Genome Project NEET Questions

Question 8. The discovery and growth of …………… Aided in the establishment of the human genome project.

1. Mechanical engineering techniques
2. Electrical engineering techniques
3. Genetic engineering techniques
4. Informational technology

Answer: 3. Genetic engineering techniques

With the discovery and establishment of genetic engineering techniques, it was possible to isolate and clone any piece of DNA, and with the availability of simple and fast techniques for determining DNA sequences, a very ambitious project of sequencing the human genome project was launched in the year 1990.

transcription mcq

Question 9. The institutes that played a key role in coordinating the human genome project were

1. European department of energy
2. Us department of energy
3. National institute of health
4. Both 2 and 3

Answer: 4. Both 2 and 3

The human genome project was coordinated by the US Department of Energy and the National Institute of Health.

Welcome Trust (UK) joined the project as a major partner. Later on, Japan, France, Germany, China, and some other countries also joined it. Thus option 4 is correct.

Question 10. Hgp was closely associated with the rapid development of a new area in biology called

1. Biotechnology
2. Bioengineering
3. Bioinformatics
4. Biological informatics

Answer: 3. Bioinformatics

The collection, storage, and analysis of DNA and protein sequencing data using the computerized system is called bioinformatics.

This is the new branch of biology that originated and evolved during the human genome project.

Question 11. In reference to hgp, elsi stands for

1. Ethical legal and social issues
2. Embedded low software index
3. Endonuclease ligase surface immunity
4. Ear lung spleen immunity

Answer: 1. Ethical legal and social issues

ELSI stands for Ethical Legal and Social Issue.

Question 12. The strategies of the human genome project include

1. Mapping
2. Sequencing
3. Alignment
4. All of these

Answer: 4. All of these

HGP includes sequencing, aligning, and mapping the genome. Frederick developed a technique through which DNA fragments get automatically sequenced called automated DNA sequencer.

DNA sequences are aligned by specialized computer-based programs.

The genetic and physical maps are generated using restriction endonuclease recognition sites and some repetitive DNA sequences known as microsatellites. Thus, option 4 is correct.

Human Genome Project NEET Questions

Question 13. The sequence of chromosome 1 was completed by

1. May 2004
2. May 2003
3. May 2005
4. May 2006

Answer: 4. May 2006

On February 12, 2001, a formal announcement about the completion of the project was made.

However, the announcement of sequencing of individual chromosomes came in May 2006 with the completion of assigning nucleotide sequences to chromosome -1.

Question 14. How were genetic and physical maps generated in hgp?

1. By using DNase
2. By using RNase
3. By using restriction endonuclease
4. By using automated dna sequences

Answer: 3. By using automated dna sequences

HGP includes sequencing, aligning, and mapping the genome. Frederick developed a technique through which DNA fragments get automatically sequenced called automated DNA sequencer.

DNA sequences are aligned by specialized computer-based programs.

The genetic and physical maps are generated using restriction endonuclease recognition sites and some repetitive DNA sequences known as microsatellites.

Question 15. Why are restriction endonucleases used in genetic engineering or in applied molecular biology?

1. As they can cut the dna at a specific base sequence.
2. As they can cut RNA at variable sites.
3. As they can cut dna at variable sites.
4. As it degrades the harmful proteins.
5. As they can join the dna fragments.

transcription mcq

Choose the correct option.

1. 1, 2 And 3
2. 3, 4 And 5
3. 2, 4 And 3
4. Only 1

Answer: 4. Only 1

Statement I describe the use of restriction enzymes in genetic engineering or in applied molecular biology. Restriction endonucleases are the special enzymes found in bacteria to degrade viral DNA.

They are used in genetic engineering or in applied molecular biology due to their ability to cut DNA at specific base sequences. Rest statements do not specify the function of restriction endonucleases

Question 16. Mapping of human chromosomes

1. Has been restricted to sex chromosomes due to small family sizes
2. Proceeded very successfully as a large number of dna markers were available
3. Has been determined that the number of linkage groups is about twice the number of chromosomes
4. Has been determined that almost whole dna is involved in the coding of genes

Answer: 2. Proceeded very successfully as a large number of dna markers were available

DNA markers are synthetically made DNA segments that are used to identify specific DNA segments in chromosomes. A large number of DNA markers are extensively used in the mapping of human chromosomes.

Question 17. Ests stands for

1. Expressed sequence tags
2. Exit sequence tags
3. Exon sequence tags
4. Both 1 and 2

Answer: 1. Expressed sequence tags

ESTs stand for Expressed Sequence Tags.

Human Genome Project NEET Questions

Question 18. Ests are

1. Genes that are expressed as dna
2. Genes that are expressed as rna
3. Exon that is expressed as dna
4. Introns that are expressed as rna

Answer: 2. Genes that are expressed as rna

ESTs are genes that are expressed as RNA

Question 19. Snps or single nucleotide polymorphisms are a

1. The location of RNA where a single base differs
2. Location on the genome where many bases of dna differ
3. Location on the genome where the single base of dna differs
4. Location of enzymes where the single base differs

Answer: 3. Location on the genome where the single base of dna differs

transcription mcq

There are about 14 million locations where single nucleotide differences occur in DNA. These locations are called SNPs or Single Nucleotide Polymorphisms.

They have the potential to find chromosomal locations for disease-associated sequences and trace human history during evolution.

Question 20. Snps can be used for

1. Tracing the association between a genetic variant and disease
2. Tracing human history
3. Evolution
4. All of the above

Answer: 4. All of the above

There are about 14 million locations where single nucleotide differences occur in DNA. These locations are called SNPs or Single Nucleotide Polymorphisms.

They have the potential to find chromosomal locations for disease-associated sequences and trace human history during evolution.

Question 21. What will be the correct gene expression pathway?

1. Gene–mRNA–transcription– translation – protein
2. Transcription–gene– translation–mrna–protein
3. Gene–transcription–mrna– translation–protein
4. Gene–translation–mrna– transcription–protein

Answer: The correct gene expression pathway is Gene – Transcription – mRNA –Translation – Protein

Question 22. In humans,

1. Non-coding dna is abundant.
2. Less than 2% of the genome codes for protein.
3. The function of more than 50% of genes is unknown.
4. Total number of genes is 30000.

Choose the correct option.

1. 1, 2, 3 and 4
2. 1 and 3
3. 1, 2 and 4
4. 1, 2 and 3

Answer: 1. All the given statements are correct for the human genome.

Question 23. The main aim of the human genome project is Karnataka

1. To introduce new genes into humans
2. To identify and sequence all the genes present in human dna
3. To develop better techniques for comparing two different human
4. dna samples
5. To remove disease-causing genes from human dna

Answer: 2. To identify and sequence all the genes present in human dna

The main aim of HGP is to determine the sequence and number of all the base pairs in the human genome

Question 24. Given below are various steps involved in sequencing human genome projects (HGP). Choose the correct order.

• Isolation of total dna.
• Cloning in suitable vectors.
• Sequence arrangement by computer.
• Formation of physical and genetic maps.
• Converting into fragments.
• Using automated sequencer.
• Using restriction endonuclease recognition sites and microsatellites.
• Completion of human genome sequencing.

Arrange the steps.

1. 1– 2 – 3 – 4 – 5 –6 –7–8
2. 1– 5– 2–6–3–7–4–8
3. 1– 2– 5–6–3–4–8–7
4. 1– 2– 5–6–3–7–8–4

Answer: 2. 1– 5– 2–6–3–7–4–8

Biology MCQ For NEET With Answers

Question 25. Commonly used vectors for cloning in human genome projects are

1. Yac (yeast artificial chromosome)
2. Bac (bacterial artificial chromosome)
3. Pac (plasmic artificial chromosome)
4. GMO (genetically modified organism)

Choose the correct option.

1. 1 And 2
2. 2 And 3
3. 3 And 4
4. 1 And 4

Answer: 1. 1 And 2

1, BAC or Bacterial Artificial Chromosomes and 2, YAC or Yeast Artificial Chromosomes are two vectors that are generally used in human genome projects for cloning large fragments of human DNA. Thus, option 1 is correct.

transcription mcq

Question 26. The chain termination method of dna sequencing was developed by

1. Sanger and Nicolson
2. Frederick sanger
3. Francois Jacob
4. Jacques Monod

Answer: 2. Frederick Sanger

Sanger’s method, which is also referred to as dideoxy sequencing or chain termination method is based on the use of dideoxynucleotides (ddNTPs) in addition to the normal nucleotides (NTPs) found in DNA.

Dideoxynucleotides are essentially the same as nucleotides except they contain a hydrogen group on the 3′ carbon instead of a hydroxyl group (OH). These modified nucleotides, when integrated into a sequence, prevent the addition of further nucleotides.

This occurs because a phosphodiester bond cannot form between the dideoxynucleotide and the next incoming nucleotide and thus, the DNA chain is terminated.

Biology MCQs with answers for NEET Regulation Of Gene Expression

Question 1. The term ‘regulation’ refers to the control over the working of

1. A gene
2. Rrna
3. Trna
4. Mrna

Answer: 1. A gene

The term regulation refers to the control over the working of a gene. Regulation of gene expression refers to a very broad term that may occur at various levels. Considering gene expression results in the formation of a polypeptide, it can be regulated at several levels.

In eukaryotes, regulation could be exerted at

“molecular basis of inheritance “

The transcriptional level (formation of primary transcript) Processing level (regulation of splicing) transport of mRNA from the nucleus to the cytoplasm Translational level

Question 2. Operon is

1. A set of closely linked genes, regulating a metabolic pathway in prokaryotes
2. The sequence of three nitrogen bases determining a single amino acid
3. The sequence of nitrogen bases in mRNA, which codes for a single amino acid
4. A gene responsible for switching on or off other genes
5. A segment of dna, specifying one polypeptide chain in protein synthesis

Answer: 1. A set of closely linked genes, regulating a metabolic pathway in prokaryotes

Operon is a set of closely linked genes that regulate a metabolic pathway in prokaryotes.

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 3. Who gave the first operon system?

1. Frederick sanger
2. Jacob and Monod
3. Both 1 and 2
4. Bateson

Answer: 2. Jacob and Monod

The first operon, lac operon was discovered by Jacob and Monod (1961).

They found out that the genetic material possesses a regulated gene a unit called an operon.

Biology MCQs with answers for NEET

Question 4. Which type of regulation takes place in lac operon?

1. Positive regulation
2. Neutral regulation
3. Negative regulation
4. Both 1 and 3

Answer: 4. Both 1 and 3

Regulation of lac operon by the repressor is referred to as negative regulation. Lac operon is under the control of positive regulation as well, by CAP (Catabolic Activator Protein).

It exerts a positive control in the lac operon because, in its absence, RNA polymerase is unable to recognize the promoter gene and switch off the lac operon. So, positive and negative types of regulations take place in the lac operon

Question 5. Jacob and Monod studied lactose metabolism in e. Coli and proposed operon concept, which is applicable for

1. Prokaryotes
2. Eukaryotes
3. Protozoans
4. All of the above

Answer: 1. Prokaryotes

The Operon model was given by Jacob and Monod (1961) for the regulation of protein synthesis in prokaryotes (bacteria)

Question 6. In the lactose operon of Escherichia coli, what is the function of the promoter?

1. Binding of gyrase enzyme
2. Binding of RNA polymerase
3. Codes for RNA polymerase
4. Processing of messenger RNA

Answer: 2. Binding of RNA polymerase

In the lactose operon of E.coli, promoter gene (P) is the actual site of the start of transcription and it is the site where RNA polymerase binds to the DNA prior to the beginning of transcription.

Biology MCQs with answers for NEET

Question 7. All of the following are part of an operon except

1. An operator
2. A promoter
3. An enhancer
4. Structural genes

Answer: 3. An enhancer

All of the following are part of an operon except an enhancer

Question 8. In the regulation of gene expression in prokaryotes,

1. Lactose acts as a suppressor for the gene expression.
2. Tryptophan acts as an inducer for the gene expression.
3. The regulatory gene is the one that produces the repressor molecule.

“molecular biology mcq “

Choose the options containing correct statements.

1. Only 1
2. Only 2
3. Only 3
4. 1 And 2
5. 1, 2 and 3

Answer: 3. Only 3

Statement 3 is correct for the regulation of gene expression in prokaryotes whereas 1 and 2 are not correct and can be corrected as Lactose acts as an inducer for the gene expression in the lac operon. Tryptophan acts as a repressor for gene expression in the trp operon

Biology MCQs with answers for NEET

Question 9. The region of the lac operon must be free (unbound) for the structural gene transcription to occur in

1. Operator
2. Promoter
3. A gene
4. Regulator

Answer: 1. Operator

The operator is a DNA sequence present between the promoter region and the first coding gene.

A regulator gene regulates the expression of structural genes by its protein product which is mostly transcription factors. This regulatory protein binds to the operator region and hence, prevents the binding and transcription.

Thus, the operator region serves as a repressor protein binding site and it must be free (unbound) for the structural gene transcription to occur.

Question 10. The functioning of structural genes is controlled by

1. Operator
2. Promoter
3. Ligase
4. Regulatory gene

Answer: 1. Operator

The operator gene allows the functioning of the operon. Operator genes are a region of DNA sequence capable of interacting with a specific repressor molecule and thus, it affects the activity of other genes downstream to it.

Question 11. In lac operon, a repressor comprises

1. Dna
2. Rna
3. Protein
4. Lactose

Answer: 3. Protein

The repressor is a regulatory protein, which is synthesized all the time by the regulator gene.

Biology MCQ For NEET With Answers

Question 12. Lactose operon is considered to be glucose sensitive due to

1. Catabolite induction
2. Allosteric inhibition
3. Anabolic inhibition
4. None of the above

Answer: 1. Catabolite induction

Glucose is a positive regulator of lactose operon. It responds to levels of glucose through catabolite induction which requires Catabolite Activator Protein (CAP) and cyclic AMP.

The binding of the CAP-cAMP complex to a promoter is required for the transcription of the lac operon.

The presence of glucose in a cell decreases cAMP concentration which in turn decreases the amount of CAP-cAMP complex.

Due to this, the promoter gets inactivated and the lac operon is turned off. Thus, due to catabolite induction, the lac operon is considered glucose sensitive.

“rna polymerase diagram “

Question 13. Repressor proteins of lac operon bind to

1. Exons
2. Introns
3. Operator
4. Structural genes

Answer: 3. Operator

Regulatory genes or i-gene produce mRNA, which makes repressor proteins that in turn, bind to the operator.

Due to the binding of the repressor to the operator, RNA polymerase cannot bind with the promoter. As a result, the working of the operon stops.

Question 14. In the lac operon model, all time or constitutively working gene is

1. Operator
2. Promoter
3. Regulator
4. Structural

Answer: 3. Regulator

In the lac operon, the regulatory gene or i-gene keeps on synthesizing the inhibitor. Thus, it is a constitutively working gene. It is the inducer (lactose) that inhibits the inhibitor by binding to its specific sites.

Biology MCQ For NEET With Answers

Question 15. Positively regulated proteins are called

1. Activator
2. Repressors
3. Necessary proteins
4. Codons

Answer: 1. Activator

The operon is regulated in both negative and positive ways. Negative control The product of the regulatory genes (repressor) shuts off the expression of genes under its control.

Positive control The product of the regulatory genes (activator) activates the expression of genes under its control. Thus, the positively regulated proteins are called activators.

Question 16. Genes that are responsible for the synthesis of a polypeptide chain are called

1. Structural gene
2. Operator gene
3. Promoter gene
4. Regulator gene

Answer: 1. Structural gene

Structural genes are the genes that are responsible for the synthesis of the polypeptide chain.

They transcribe to give mRNA which contains codons for amino acids

Biology MCQ For NEET With Answers

Question 17. Match the components of ‘lac operon’. Coli is given under column 1 with their functions listed in column 2. Choose the option from the codes given below.

Answer: 3. 1–4, 2–1, 3–5, 4–2

Question 18. The sequence of the structural genes in the lac operon concept is

1. Lac a, lac y, lac z
2. Lac a, lac z, lac y
3. Lac y, lac z, lac a
4. Lac z, lac y, lac a

Answer: 4. Lac z, lac y, lac a

Lac operon (lactose operon) is a genetic system of E. coli, which is responsible for the uptake and initial catabolism of lactose. The lac operon consists of three structural genes in a sequence of lac Z, lac Y, lac A

Question 19. Lactose is transported into cells through

1. Β-galactosidase
2. Permease
3. Transacetylase
4. Transferase

Answer: 2. Permease

Lactose is transported into the cells by the enzyme permease. Permease enzyme is produced by the structural gene Y

“which one of the following is not applicable to rna “

Question 20. Consider the following statements.

Structural genes produce mRNA when the operator gene is turned on by an inducer.
The promoter gene base sequence determines which strand of dna acts as a template.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 3. Both statements 1 and 2 are correct

Biology MCQ For NEET With Answers

Question 21. The lac operon is turned on when allolactose molecules bind to

1. Promoter site
2. Operator site
3. Mrna
4. Repressor protein

Answer: 4. Repressor protein

The repressor protein binds to the operator region of the operon and prevents RNA polymerase from transcribing the operon.

In the presence of an inducer, such as lactose or allolactose, the repressor is inactivated by interaction with the inducer. This allows RNA polymerase access to the promoter and transcription proceeds. Thus, the lac operon is turned on when allolactose molecules bind to the repressor protein

Question 22. In the lac operon, the structural genes are switched off when

1. The repressor binds to the operator
2. Repressor binds to the promoter
3. Repressor binds to regular
4. Repressor binds to inducer
5. All of the above

Answer: 1. Repressor binds to the operator

The structural genes remain switched off and do not proceed with transcription till the repressor remains bound to the operator

Question 23. The lactose (lac) operon is regulated by

1. Lac repressor only
2. Lac repressor and cap-cgmp complex
3. Lac repressor and cap-camp complex
4. Cap-camp and cap-cgmp complex

Answer: 3. Lac repressor and cap-camp complex

Two regulators turn the operon on and off in response to lactose and glucose levels, the lac repressor, and the CAP–cAMP complex.

The lac repressor acts as a lactose sensor. It normally blocks transcription of the operon but stops acting as a repressor when lactose is present.

Glucose is a positive regulator of lactose operon. It responds to levels of glucose through catabolite induction which requires Catabolite Activator Protein (CAP) and cyclic AMP.

The binding of the CAP-cAMP complex to a promoter is required for the transcription of the lac operon.

The presence of glucose in a cell decreases cAMP concentration which in turn decreases the amount of CAP-cAMP complex.

Due to this, the promoter gets inactivated and the lac operon is turned off. Thus, due to catabolite induction, the lac operon is considered glucose sensitive.

“which of the following is an initiation codon “

Question 24. Match the following columns.

NEET Biology Mcq

Answer: 1. A-4, B-1, C-2

Question 25. In eukaryotes, the genes are regulated by

1. Promoters
2. Operator
3. Repressors
4. Enhancers

Answer: 4. Enhancers

Enhancers are positive DNA regulatory sequences that control tissue-specific gene expression.

These elements act independently of their orientation and distance relative to the promoters of target genes. So, the genes are regulated by enhancers in eukaryotes.

Question 26. Negatively regulatory proteins are known as

1. Repressor
2. Accessory proteins
3. Catalytic proteins
4. Both 1 and 3

Answer: 1. Repressor

The repressor is a negative regulatory protein, which is synthesized all the time by the regulator gene. It is meant to block the operator gene so that the structural genes cannot form mRNA.

Question 27. In the lac operon model, feedback repression is

1. When the end product starts the process
2. When the end product does not form
3. When the end product halts the process
4. When the start product stops the process

Answer: 3. When the end product halts the process

The end product is often utilized in some reactions so, it rarely accumulates. However, in the lac operon, it accumulates and stops the operon system. It is called feedback inhibition or repression.

Question 28. When tryptophan is present, what happens in the trp operon?

1. Repressor becomes inactive
2. The repressor is unable to bind to the operator
3. Transcription of structural genes occur
4. The repressor is able to bind to the operator

Answer: 4. Repressor is able to bind to the operator

When tryptophan is present in the cell, two tryptophan molecules bind to the trp repressor, which changes shape to bind to the trp operator.

The binding of the tryptophan-repressor complex at the operator physically prevents the RNA polymerase from binding and transcribing the downstream genes.

NEET Biology Mcq

Question 29. E. Coli cells with a mutated z-gene of the lac operon cannot grow in a medium containing only lactose as the source of energy because

1. In the presence of glucose, E. coli cells do not utilize lactose
2. They cannot transport lactose from the medium into the cell
3. The lac operon is constitutively active in these cells
4. They cannot synthesize functional beta-galactosidase

Answer: 4. They cannot synthesize functional beta-galactosidase

Lac Z (3063 bp) codes for the enzyme β-galactosidase which breaks lactose into glucose and galactose to be utilized in the cell.

Therefore, E. coli cells with mutated Z-genes cannot grow in a medium containing only lactose as the source of energy because they cannot synthesize functional β-galactosidase

Question 30. Why cannot glucose and galactose act as an inducer for lac operon?

1. Because they cannot bind with the repressor
2. Because they can bind with the repressor
3. Because they can bind with the operator
4. Because they can bind with the regulator

Answer: 1. Because they cannot bind with the repressor

An inducer binds with the repressor protein and prevents the repressor protein from binding with the operator.

Glucose and galactose cannot act as an inducer because they do not have the binding sites for attaching to the repressor protein

Question 31. Given below are statements regarding lac operon. Identify the correct statements.

1. Glucose or galactose may bind with the repressor and inactivate it.
2. In the absence of lactose, the repressor binds with the operator region.
3. The z-gene codes for permease.
4. This was elucidated by Francois Jacob and Jacques Monod.

Choose the option containing the correct statements.

1. 2 And 3
2. 1 And 3
3. 2 And 4
4. 1 And 2

Answer: 3. The z-gene codes for permease.

Statements 2 and 4 are correct, but 1 and 3 are incorrect regarding the lac operon.

Incorrect statements can be corrected as Lactose or allolactose binds with the repressor and induces the lac operon system. The Z-gene codes for β-galactosidase.

NEET Biology Mcq

Question 32. The gene not expressing any protein is known as

1. Epistatic gene
2. Hypostatic gene
3. Pseudogene
4. None of the above

Answer: 3. Pseudogene

Pseudogenes are inheritable genetic elements that are similar to functional genes but are non-functional as they do not encode proteins.

Their biogenesis results from the duplication of a parental gene or the retrotransposition of an mRNA sequence into different genomic loci.

Biology MCQs with answers for NEET Translation

Question 1. Identify the process associated with the synthesis of enzymes and proteins.

1. Translation
2. Replication
3. Transduction
4. Transcription

Answer: 1. Translation

All enzymes are proteins and the synthesis of proteins from RNAs is called translation.

Question 2. The site of protein synthesis is the

1. Chloroplast
2. Ribosomes
3. Pyrenoids
4. Mitochondria

Answer: 2. Ribosomes

Protein synthesis occurs over ribosomes which are also called protein factories. Ribosomes may form groups of 5-20 called polyribosomes. The ribosomes of a polyribosome are held together by a strand of mRNA

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 3. Translation refers to the

1. Formation of amino acid from RNA
2. Formation of RNA from DNA
3. Formation of DNA from DNA
4. Both 2 and 3

Answer: 1. Formation of amino acid from RNA

Translation refers to the polymerization of amino acids to form a polypeptide from RNA.

“molecular basis of inheritance “

Question 4. The first phase of translation is

1. Recognition of dna molecule
2. Aminoacylation of tRNA
3. Recognition of an anticodon
4. Binding of mRNA to the ribosome

Answer: 4. Binding of mRNA to the ribosome

The first phase of translation is aminoacylation of tRNA, i.e. Activation of amino acids and the formation of aa-trna complex.

In the presence of an enzyme aminoacyl tRNA synthetase, the amino acid (aa) is activated, and then each amino acid is attached to the specific tRNA molecule at the 3′cca end to form the aminoacyl-trna complex. The reaction needs ATP.

This process is thus, called charging of tRNA or aminoacylation of tRNA.

Question 5. The type of RNA specifically responsible for directing the proper sequence of amino acids in protein synthesis is

1. Ribosomal RNA
2. Messenger RNA
3. Chromosomal rna
4. Viral RNA

Answer: 2. Messenger RNA

Messenger RNA (mRNA) brings coded or genetic information from the the nucleus or from dna to the cytoplasm and takes part in protein synthesis. They are responsible for directing the proper sequence of amino acids in protein synthesis.

Biology MCQs with answers for NEET

Question 6. Charging (aminoacylation) of tRNA involves the attachment of

1. Amino acid to mRNA
2. Amino acid to trna
3. Amino acid to rRNA
4. Acidic amino acid to the ribosome

Answer: 2. Amino acid to trna

The first phase of translation is aminoacylation of trna, i.e. Activation of amino acids and the formation of aa-trna complex.

In the presence of an enzyme aminoacyl trna synthetase, the amino acid (aa) is activated, and then each amino acid is attached to the specific trna molecule at 3′/cca end to form aminoacyl-trna complex. The reaction needs ATP.

This process is thus, called charging of trna or aminoacylation of trna.

“molecular biology mcq “

Question 7. 70S ribosome and 80s ribosome, respectively are found in

1. Prokaryotes and eukaryotes
2. Eukaryotes and prokaryotes
3. Only prokaryotes
4. Plants and animals

Answer: 1. Prokaryotes and eukaryotes

Messenger RNA (mRNA) brings coded or genetic information from the nucleus or from DNA to the cytoplasm and takes part in protein synthesis. They are responsible for directing the proper sequence of amino acids in protein synthesis

Question 8. Aminoacyl synthetase is responsible for

1. Formation of peptide bond
2. Binding of mRNA to ribosomes
3. Attaching an amino group to an amino acid
4. Joining of amino acid to trna

Answer: 4. Joining of amino acid to trna

The first phase of translation is aminoacylation of tRNA, i.e. activation of amino acids and the formation of AA-tRNA complex.

In the presence of an enzyme aminoacyl tRNA synthetase, the amino acid (AA) is activated, and then each amino acid is attached to the specific tRNA molecule at the 3′/CCA end to form the aminoacyl-tRNA complex. The reaction needs ATP. This process is thus, called charging of tRNA or aminoacylation of tRNA.

Biology MCQs with answers for NEET

Question 9. 80S ribosome is formed of subunits

1. 30S and 50s
2. 40S and 40s
3. 20S and 60s
4. 40S and 60s

Answer: 4. 40S and 60s

A eukaryotic ribosome has a large subunit that sediments at 60S and a small subunit that sediments at 40S. The whole structure sediments at 80S and not 100S. In the same way, the prokaryotic ribosome has two subunits.

The large subunit sediments at 50S and the small subunit sediments at 30S, but the two together (that is, the whole ribosome) sediments at 70S, not 80S.

“rna polymerase diagram “

Question 10. A ribosome that acts as a catalyst or ribozyme is

1. 40S rRNA
2. 50S rRNA
3. 70S rRNA
4. 23S rRNA

Answer: 4. 23S rRNA

The 23S rRNA is 2904 base pair long and it is a component of bacterial ribosome.

Ribosomal peptidyl transferase activity resides in 23S rRNA for peptide bond formation between two amino acids during
translation.

Some naturally occurring ribozymes include Peptidyl transferase 23S rRNA RNase Group 1 and Group 2 introns

Question 11. Polysomes are

1. Cell organelles in prokaryotes
2. Cell organelles in eukaryotes
3. Chain of nucleosomes
4. Ribosomes attached to mRNA

Answer: 4. Ribosomes attached to mRNA

A polyribosome (polysome or orgasm) is a complex of a mRNA molecule and two or more ribosomes that help to translate mRNA instructions into polypeptides. So, polysomes are ribosomes attached to mRNA.

Question 12. Consider the following statements.

Polyribosomes are formed during active protein synthesis.
Different ribosomes of polyribosomes are connected with trna.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 1. Statement 1 is correct, but 2 is incorrect

The incorrect statement can be corrected as The different ribosomes of a polyribosome are connected with a 10-20 Å thick strand of messenger or mRNA and its maintenance requires energy.

Polyribosomes are formed during periods of active protein synthesis when a number of copies of the same polypeptide are required.

Biology MCQ For NEET With Answers

Question 13. Aminoacylation often is essential for

1. Replication of RNA
2. Formation of peptide bond
3. Splicing
4. Initiation of transcription
5. Termination

Answer: 2. Formation of peptide bond

Charging or aminoacylation of tRNA is essential for protein synthesis, i.e. Polypeptide formation through the formation of peptide bonds between amino acids.

“which one of the following is not applicable to rna “

Question 14. Proteins are formed by

1. Peptide link
2. Glycosidic link
3. Phosphate link
4. Phosphodiamine linkage

Answer: 1. Peptide link

Proteins are formed by the joining of amino acids through a peptide bond

Question 15. Which enzyme takes part in peptide bond formation?

1. Protease
2. Peptidase
3. Nitrogenase
4. Peptidyl transferase

Answer: 4. Peptidyl transferase

Peptidyl transferase is an enzyme whose activity is carried out by ribosomes. It forms peptide bonds between adjacent amino acids using tRNAs during the translation process of protein biosynthesis.

Question 16. During the translation process, the incoming trna complexes other than aa 1 -trna get first attached to

1. A-site
2. P-site
3. E-site
4. Q-site

Answer: 1. A-site

During the translation process, the incoming tRNA complexes other than AA 1 -tRNA get first attached to the A-site. A-site is the aminoacyl site, also called the acceptor site. In this site, new amino acids are formed.

Biology MCQ For NEET With Answers

Question 17. During translation, the p-site on the ribosome receives directly

1. Amino acids
2. Aa 1-trna
3. Mrna with codon
4. Mrna with anticodon

Answer: 2. Aa 1-trna

P-site is the peptidyl transfer or donor site, which holds the growing amino acids chain and makes the peptide bond between two amino acids. Activated tRNA, i.e.

AA 1 -tRNA occupies the P-site. Thus, the P-site on the ribosome receives directly AA1 -tRNA during translation.

Question 18. Amino acids are activated by

1. Adp
2. Amp
3. Atp
4. Special proteins

Answer: 3. Atp

Amino acids are activated by ATP. They become activated by binding with aminoacyl tRNA synthetase enzyme in the presence of ATP.

Question 19. During translation initiation in prokaryotes, a gtp molecule is needed in

1. Association of 50s subunit of the ribosome with the initiation complex
2. Formation of formyl-met-trna
3. Binding of 30s subunit of the ribosome with mRNA
4. Association of 30 s mRNA with formyl- met-trna

Answer: 4. Association of 30 s mRNA with formyl- met-trna

For the formation of an initiation complex during the translation of mRNA, GTP is also required. The initiation codon, AUG codes for the formylmethionine in prokaryotes.

The initiation of a polypeptide chain in prokaryotes is always brought about by the amino acid methionine, but it has to be formyl methionine (met). This methionine binds with tRNA-met to form feet-tRNA-met.

“class 12th biology molecular basis of inheritance “

This met-tRNA-feet complex binds with the mRNA-30S subunit complex using initiation factors IF 2 IF1 and GTP.

Question 20. Non-proteinaceous enzyme that acts as a catalyst for the formation of peptide bond

1. Spliceosome
2. Ribozyme
3. Rna poly-1
4. Rna poly-3

Answer: 2. Ribozyme

Formation of the peptide bond that links each amino acid is catalyzed by the 23S RNA (ribozyme) molecule in the large subunit of the ribosome

Question 21. The ion required to keep the two ribosomal units together during protein synthesis is

1. K+
2. Mg2+
3. Cl
4. All of these

Answer: 2. Mg2+

The two subunits of ribosomes come together only at the time of protein formation. The phenomenon is called association. Mg 2+ is essential for it

Question 22. Consider the following statements.

• Anticodon binds with codons by hydrogen bonds.
• During translation, ribosomes move over mRNA so that all codons on mRNA are exposed.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 3. Both statements 1 and 2 are correct

Biology MCQ For NEET With Answers

Question 23. Termination of protein synthesis occurs

1. At stop signal
2. Tata box
3. Due to the release factor
4. At the appearance of GUG and Aug codons

Choose the option containing the correct combination.

1. 1 and 3
2. 2 and 3
3. 3 and 4
4. 1, 2, 3 and 4

Answer: 1. 1 and 3

1 and 3 represent the correct combination for termination. Stop signals are the non-sense codons on mRNA and releasing factor
recognize the stop signals. There are three non-sense codons, i.e. UAA, UAG, and UGA.

These codons are not recognized by any of the tRNAs. There are two prokaryotic release factors, RF 1 -specific for UAG and UAA and
RF 2-specific for UAA and UGA. In eukaryotes, there is only one release factor eRF.

Question 24. Given below are sets of components and their types in prokaryotes and eukaryotes. Identify the incorrect set. Component > prokaryotes > eukaryotes

1. Initiation factor > if1 and if2 > if3
2. Termination or release factor > rf1 and rf 2 > erf1
3. Type of cistron > polycistronic > monocistronic
4. First amino acid > formylated methionine > methionine

Answer: 1. Identify the incorrect set. Component > prokaryotes > eukaryotes

“which of the following is an initiation codon “

Option (a) shows incorrect matching and can be corrected as Prokaryotic initiation factors are IF-1, IF-2, and IF-3.

In contrast in eukaryotes, these are elF1, elF 2a,− elF c, elF 3, elF 4a,− elF 4 f, elF 5, and elF 6 Rest other options are the correct matching of prokaryotes and eukaryotes translation

Question 25. Which of the following set of options is used in translation?

1. RNA, tRNA, rRNA
2. mRNA, tRNA, rRNA
3. mRNA, tRNA, RNA
4. hNRNA, rRNA, tRNA

Answer: 2. mRNA, tRNA, rRNA

Post-transcriptional processing converts hnRNA into functional mRNA which then participates in translation (protein synthesis). mRNA, tRNA, and rRNA are the functional RNAs that take part in translation. hnRNA (heterogeneous nuclear RNA) does not function until it undergoes processing.

NEET Biology Mcq

Question 26. Where is the untranslated region present on mRNA?

1. 5′ End
2. 3′ End
3. Before start codon
4. After stop codon

Choose the correct option.

1. 1 and 2
2. 2 and 3
3. 3 and 4
4. 1, 2, 3 and 4

Answer: 4. 1, 2, 3 and 4

Untranslated regions of mRNA are present on the 5′ and 3′ ends. These sequences do not participate in the translation process.

At the 5′ site, they (untranslated region) are present before the start codon and at the 3′ site, they are present after the termination codon. These regions are very important for efficient translation.

Question 27. Given below are different release factors and their functions.

1. Rf-1 – recognize stop codons uaa and ag
2. Rf-2 – recognize stop codons uaa and uga
3. Rf-3 – gtp binding protein that binds rf-1 and rf-2 to ribosomes
4. Erf-1 – recognize all 3 termination codons.

Choose the option containing incorrectly matched pairs.

1. 1 and 2
2. 3 and 4
3. 2 and 3
4. None of them

Answer: 2. Rf-2 – recognize stop codons uaa and uga

Question 28. What would happen if, in a gene encoding a polypeptide of 50 amino acids, the 25th codon (uu) is mutated to use?

1. A polypeptide of 25 amino acids will be formed
2. A polypeptide of 24 amino acids will be formed
3. Two polypeptides of 24 and 25 amino acids will be formed
4. A polypeptide of 49 amino acids will be formed

Answer: 2. A polypeptide of 24 amino acids will be formed

UAA is the stop codon. So, at 25th amino acid, the synthesis of polypeptide would stop. Thus, a polypeptide of 24 amino acids will be
formed after mutation.

UAA does not code for any amino acid. If UAU is mutated to UAA, then the polypeptide chain will be terminated at that point because tRNA cannot bring the next amino acid.

Question 29. Which of the following characteristics are required for protein synthesis?

1. Dna to provide the base sequence.
2. 20 Types of amino acids.
3. Genetic type of RNA.
4. Non-genetic types of RNA such as mRNA, rRNA, and trna.
5. Atp/gtp as a source of energy.

Choose the correct option 

1. 1, 2, and 3 are required
2. 1, 2, 4, and 5 are required
3. 3 and 5 are required
4. 1 and 5 are required

Answer: 2. 1, 2, 4, and 5 are required

All given characters are required for protein synthesis except III. The incorrect character can be corrected as Genetic RNAs do not play any role in protein synthesis.

NEET Biology Mcq

Question 30. Choose the incorrect statement in the process of protein synthesis.

1. After uncoiling of the dna molecule, one strand acts as a template for the formation of mRNA
2. In the presence of dna polymerase enzyme, the mRNA is formed based on the triplet codes
3. The mRNA that leaves the nucleus reaches the cytoplasm and gets attached to the 30s ribosomal subunit
4. The amino acids are transferred from the intracellular amino acid pool to the active ribosomes by the trna
5. The translation is the process in which proteins are synthesized from the RNA

Answer: 2. In the presence of dna polymerase enzyme, the mRNA is formed based on the triplet codes

The statement in option 2 is incorrect and can be corrected during protein synthesis, Polypeptides are formed based on
triplet codons on mRNA.

In the presence of RNA polymerase, mRNA is formed during transcription. Rest statements are correct regarding the process of protein synthesis

Question 31. Choose the correct options for a, b, c, and d.

A–uncharged trna, b–charged trna, c–3′ end, d–5′ end
A–charged trna, b–uncharged trna, c–3′ end, d–5′ end
A–charged trna, b–uncharged trna, c–5′ end, d–3′ end
A–charged trna, b–charged trna, c–5′ end, d–3′ end
Answer: 1. A–Uncharged tRNA, B–Charged tRNA, C–3′ end, D–5′ end

Biology MCQs with Answers for NEET Genetic Code And RNA

Question 1. A sequence of three base codes along the DNA molecule is called

1. Genetic code
2. Gene pool
3. Genetic drift
4. Genome

Answer: 1. Genetic code

The relationship between the sequence of bases in DNA or RNA and the sequence of amino acids in a polypeptide chain is called genetic code. It is a sequence of three base codes

Question 2. Who was the first one to suggest that genetic codes are a triplet?

1. George Gamow
2. Crick
3. Ochoa
4. Nirenberg

Answer: 1. George Gamow

“molecular basis of inheritance “

Question 3. The genetic code is a triplet code. Three adjacent bases which specify an amino acid are called as

1. Recon
2. Muton
3. Intron
4. Codon

Answer: 4. Codon

Three bases in the genetic code that specify an amino acid are called codons.

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 4. Consider the following statements.

1. Six codons do not code for any amino acid.
2. Codon is read in mRNA in a continuous fashion.
3. Three codons function as stop codons.
4. The initiator codon AUG codes for methionine.

Choose the option containing an incorrect statement.

1. 1, 2 and 4
2. 1, 2 and 3
3. 2, 3 and 4
4. Only 2
5. Only 1

Answer: 3. 2, 3 and 4

All statements are correct except The incorrect statement can be corrected as 61 codons code for amino acids and 3 codons do not code for any amino acids, hence they function as stop codons.

Question 5. Genetic code is

1. The sequence of nitrogenous bases on hnRNA
2. The sequence of nitrogenous bases on tRNA
3. The sequence of nitrogenous bases on rRNA
4. The sequence of nitrogenous bases on DNA

Answer: 4. Sequence of nitrogenous bases on DNA

“molecular biology mcq “

Genetic code comprises the sequence of nitrogenous bases (A, G, T, C, U) on DNA. These bases are arranged in a different manner to form a triplet codon.

Biology MCQ For NEET With Answers

Question 6. Genetic code determines

1. Structure of proteins
2. Structure of amino acids
3. The sequence of amino acids
4. Metabolic pathways

Answer: 3. Sequence of amino acids

Genetic code is the set of rules by which genetic information in DNA is translated into proteins within the cell.

This information is present in the form of a series of triplets of nitrogenous bases in DNA, from which a complementary sequence of codons in messenger RNA is transcribed.

The sequence of these codons, in turn, determines the sequence of amino acids during protein synthesis.

Question 7. The genetic code was explained by

1. Nirenberg
2. Matthaei
3. Both 1 and 2
4. Khorana

Answer: 3. Both 1 and 2

Nirenberg and his post-doctoral fellow Heinrich Matthaei explained the genetic code for the first time. Thus, option (c) is correct

Question 8. The initiation codon in eukaryotes is

1. GAU
2. AGU
3. AUG
4. UAG

Answer: 3. AUG

AUG codes for methionine and acts as an initiation codon in eukaryotes during translation. Thus, it has dual functions.

Question 9. Genetic code is

1. Degenerate, overlapping, ambiguous
2. Degenerate, non-overlapping, unambiguous
3. Universal, overlapping, ambiguous
4. Degenerate, non-overlapping, ambiguous

Answer: 2. Degenerate, non-overlapping, unambiguous

Salient features of the genetic code are as follows

The codon is a triplet, i.e. 61 codons code for amino acids, and 3 codons function as stop codons. One codon codes for only one particular amino acid, hence the code is unambiguous, non-overlapping, and specific. Some amino acids are coded by more than one codon, hence the codons are degenerated. There are no punctuations in the triplet codon. The code is nearly universal. For example, from bacteria to humans, UUU codes for phenylalanine (phe). Some exceptions to this rule are found in mitochondria and protozoan’s codons.

Biology MCQ For NEET With Answers

Question 10. Genetic code consists of

1. Adenine and guanine
2. Cytosine and uracil
3. Cytosine and guanine
4. All of the above

Answer: 4. All of the above

Genetic code is the relationship between the amino acid sequence in a polypeptide chain and the base sequence of mRNA. I include adenine, guanine, cytosine, uracil, and thymine.

“molecular biology mcq “

Question 11. Which of the following is a non-sense codon?

1. AUG
2. USA
3. UAG
4. AGG

Answer: 3. UAG

A codon for which no normal tRNA molecule exists is called a non-sense codon.

It causes termination of translation. There are three non-sense codons, viz. amber (UAG), ochre (UAA), and opal (UGA).

Question 12. Which one of the following has dual functions?

1. AUG
2. AUC
3. ACU
4. ACA

Answer: 1. AUG

AUG codes for methionine and acts as an initiation codon in eukaryotes during translation. Thus, it has dual functions.

Question 13. Which of the following amino acids has a single codon?

1. Tyrosine
2. Tryptophan
3. Serine
4. Cysteine

Answer: 2. Tryptophan

Only tryptophan (UGG) and methionine (AUG) are specified by single codons.

Cysteine and tyrosine are coded by two codons, while serine is coded by 6 codons

Biology MCQ For NEET With Answers

Question 14. Which triplet codon does not have a tRNA associated with it?

1. UAA
2. UUA
3. UUU
4. AUU
5. GUU

Answer: 1. UAA

UAA is the termination codon and thus, no tRNA and no amino acid is associated with it

Question 15. The triplet UUU codes for

1. Leucine Odisha
2. Methionine
3. Phenylalanine
4. Glycine

Answer: 3. Phenylalanine

It is the first genetic code discovered by Nirenberg. It codes for phenylalanine

Question 16. Which sequence of codons specifies leucine-threonine-proline?

1. CUC-GCU-CCC
2. AAA-ACC-CCC
3. UUG-AGC-UAG
4. CUA-ACA-CCU

Answer: 4. CUA-ACA-CCU

It is the first genetic code discovered by Nirenberg. It codes for phenylalanine

Question 17. From bacteria to men, a nearly universal code for phenylalanine is

1. UUU
2. UUA
3. UUG
4. CUU

Answer: 1. UUU

It is the first genetic code discovered by Nirenberg. It codes for phenylalanine.

“molecular biology mcq “

Question 18. Match the names of triplet codons listed under Column 1 with the amino acids given under Column 2. Choose the correct option from the codes given below.

Answer: 2. 1-5, 2-4, 3-3, 4-2.

Question 19. Which of the following groups of codons code for amino acid serine?

1. CUU, CUC, CUA and CUG
2. UAU, UAC, UGU, and UGC
3. UCU, UCC, UCA and UCG
4. UGU, UGC, UGA and UAG
5. GUU, GUC, GCU, and GCC

Answer: 3. UCU, UCC, UCA and UCG

The codons UCU, UCC, UCA, UCG, AGU, and AGC, are all codes for the amino acid serine.

Question 20. The number of codons that code different amino acids is

16
31
61
64

Answer: 3. 61

There are 64 triplet codons which code for only 20 amino acids. Out of 64, three codons are non-sense codons as they do not specify any amino acid. Thus, only 61 codons code for amino acids.

NEET Biology Mcq

Question 21. The starting codon is universal means HP

1. It is the same universally for all organisms
2. Two or more codons
3. Any variable code is called starting which can start protein synthesis
4. All codons originated from the same starting codon

Answer: 1. It is the same universally for all organisms

Starting codon is universal means it is the same universally for all organisms.

Question 22. Which of the following statements is correct regarding genetic code?

1. It is the initiation codon which also codes for phenylalanine
2. There are 64 triplet codons and only 20 amino acids
3. Three random nitrogen bases specify the placement of one amino acid
4. UAA is the non-sense codon which also codes for methionine

Answer: 2. Three random nitrogen bases specify the placement of one amino acid

“molecular biology mcq “

The statement in option 2 is correct regarding genetic code. There are 64 triplet codons which code for only 20 amino acids.

This is due to the degeneracy of code as some amino acids are influenced by more than one codon. Only tryptophan and methionine are specified by a single codon.

Rest statements are not correct regarding genetic code and can be corrected as UUU is not the initiation codon, three
random nitrogen bases specify one codon and UAA does not code for any amino acid.

Question 23. Given below are different codons and amino acids coded by them.

1. ACG – Threonine
2. GAG – Glycine
3. UAU – Tyrosine
4. CGU – Leucine

Choose the option containing incorrectly matched pairs.

1. 1 and 3
2. 2 and 4
3. 3 and 4
4. 2 and 3

Answer: 2. 2 and 4

2 and 4 are incorrectly matched pairs and can be corrected as GAG codes for glutamic acid and CGU codes for arginine. The rest others are correctly matched pairs.

Question 24. Which one of the following pairs of codons are correctly matched with their function or the signal for the particular amino acid?

1. GUU, GCU–Alanine
2. UAG, UGA–Stop
3. AUG, ACG–Start-Methionine
4. UUA, UCA–Leucine

Answer: 2. UAG, UGA–Stop

Option 2 is correctly matched pairs. UAG and UGA are stop codons. They do not code for any amino acid.

“molecular biology mcq “

Rest options are not correctly matched pairs and can be corrected as GUU codes for valine and GCU codes for alanine. AUG is a start codon that codes for methionine but ACG codes for threonine.

UUA codes for leucine but UCA codes for serine.

NEET Biology Mcq

Question 25. Which one of the following statements is not correct?

1. Cysteine is coded by UGU and UGC codons
2. Tyrosine is coded by UAU and UAC codons
3. UAA codon codes for lysine
4. UGG codon codes for tryptophan

Answer: 3. UAA codon codes for lysine

The statement in option 3 is not correct and can be corrected as UAA is a stop codon. It does not specify any amino acid and thus, is called a non-sense codon. Rest statements are correct

Question 26. Match the codons in Column 1 with Column 2 their respective amino acids and choose the correct answer.

Answer: 1. A–3, B–4, C–1, D–5, E–2

Question 27. According to the wobble hypothesis,

1. The process of polypeptide chain elongation has been established
2. The first base is unstable
3. The second base is the most unstable
4. The third base is the most unstable

Answer: 4. Third base is the most unstable

“molecular biology mcq “

The Wobble hypothesis discovered by Francis Crick states that the rules of base pairing are relaxed at the third position, i.e. it is most unstable. Thus, a base can pair with more than one complementary bases

Question 28. Which of the following codon anticodon combinations shows the wobble phenomenon?

1. UUU/AAA
2. GCA/CGA
3. AAU/UUA
4. CCA/GGU

Answer: 2. GCA/CGA

According to the wobble hypothesis, in codon-anticodon pairing, the third base may not be complementary. Thus, the wobble hypothesis applies to option 2, which shows A is being paired with A only.

Question 29. Genetic code is universal, it means

1. It is the same for all living organisms
2. It is the same for a specific protein
3. It is the same for triplet codon
4. None of the above

Answer: 1. It is the same for all living organisms

The code is nearly universal which means it is the same for all living organisms. For example, from bacteria to humans, UUU codes for phenylalanine (Phe).

Question 30. Consider the following statements.

1. Genetic code is unambiguous.
2. One codon codes for more than one amino acid.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 1. Statement 1 is correct, but 2 is incorrect

“molecular biology mcq “

Question 31. Because most amino acids are represented by more than one codon, the genetic code is

1. Overlapping
2. Wobbling
3. Degenerate
4. Generate

Answer: 3. Degenerate

All amino acids are specified by more than one codon (except tryptophan and methionine).

Hence, they are degenerate.

Since there are 64 possible combinations of the four different nucleotides in sets of three, there is a redundancy in the system, which means that most amino acids can be coded by more than one triplet.

Question 32. Out of the total 64 codons, 61 code for 20 amino acids, this suggests

1. Degeneracy Of Codons
2. Overlapping Of Codons
3. Redundancy Of Codons
4. Both 1 and 3

Answer: 3. Redundancy Of Codons

All amino acids are specified by more than one codon (except tryptophan and methionine). Hence, they are degenerate.

Since there are 64 possible combinations of the four different nucleotides in sets of three, there is a redundancy in the system, which means that most amino acids can be coded by more than one triplet.

Question 33. The terminator codons are

1. UAA, UAG, UGA
2. AUG, UAG, UGA
3. UAC, AUG, UAG
4. DCC, UAA, CAC
5. AUG, ACG, GAG

Answer: 1. UAA, UAG, UGA

UAA (ochre), UAG (amber), and UGA (opal) are the three codons, which bring about the termination of the polypeptide chain and thus, are called terminator codons.

Question 34. If there are 999 bases in an RNA that codes for a protein with 333 amino acids and the base at position 901 is deleted such that the length of the RNA becomes 998 bases, how many codons will be altered?

1. 1
2. 11
3. 33
4. 333

Answer: 3. 33

999 bases in RNA code for a protein with 333 amino acids. If the base at the 901 position is deleted, the first 900 bases will be normal, while the bases after the 901th position will be altered that is 99 bases will be altered.

3 bases = 1 codon. So, 99 bases = 33 codons will be altered 901 position

“rna polymerase diagram “

Question 35. Given below are the codons and their common names.

1. UAA – Ochre
2. UAG – Opal
3. UGA –Amber

Choose the option containing incorrectly matched pairs.

1. Only 1
2. Only 3
3. 2 and 3
4. 1, 2 and 3

Answer: 3. 2 and 3

2 and 3 are incorrectly matched pairs and can be corrected as UAG is called amber and UGA is called opal. The rest other is a correctly matched pair.

Question 36. Which form of RNA has a structure resembling clover leaf?

1. rRNA
2. hnRNA
3. mRNA
4. tRNA

Answer: 4. tRNA

The two-dimensional structure of tRNA looks like a clover leaf, hence its structure is referred to as a cloverleaf structure. It was given by Holley in 1965.

Question 37. DHU arm is also called

1. Dihydrouracil arm
2. Dihydroxyuracil arm
3. Dehydroxyuracil arm
4. Dihydroperoxyuracil arm

Answer: 1. Dihydrouracil arm

DHU arm is the base pair segment of the cloverleaf structure of transfer RNA. It has a loop containing 5,6-dihydrouracil attached to it.

Question 38. Which site of the tRNA molecule binds to a mRNA molecule?

1. Codon
2. Anticodon
3. 5′ end of tRNA
4. 3′ end of tRNA

Answer: 2. Anticodon

A tRNA molecule is held tightly at the A- and P-sites only if its anticodon forms base pairs with a complementary codon (allowing for wobble) on the mRNA molecule that is bound to the ribosome.

“which one of the following is not applicable to rna “

Question 39. tRNA contains

1. 5 unpaired bases
2. 7 unpaired bases
3. 3 unpaired bases
4. 4 unpaired bases

Answer: 3. 3 unpaired bases

Each tRNA contains a set of three unpaired nucleotide bases called an anticodon. The anticodon of a given tRNA can bind to one or a few specific mRNA codons.

Question 40. Anticodon occurs in

1. tRNA
2. mRNA
3. rRNA
4. DNA

Answer: 1. tRNA

Codons are present on mRNA and anticodon on tRNA.

Question 41. Consider the following statements.

• The D-arm of tRNA is a highly variable region.
• T ψ C arm of tRNA contains thymidine, pseudouridine, and cytidine.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 3. Both statements 1 and 2 are correct

Question 42. How many types of anticodons are present on tRNAs for stop codons?

1. One
2. Two
3. Three
4. None of these

Answer: 4. None of these

There are no anticodons on tRNA to read stop codons on mRNA (UAA, UAG, UGA). This implies there is no tRNA for the stop codon. Thus, option (4) is correct

Question 43. What is true about tRNA?

1. It binds with an amino acid at its 3-end
2. It has five double-stranded regions
3. It has a codon at one end which recognizes the anticodon on messenger RNA
4. It looks like a clover leaf in the three-dimensional structure

Answer: 1. It binds with an amino acid at its 3-end

Option (a) is true about tRNA. Anticodon is the sequence of three nucleotides in a transfer RNA molecule that pairs with a complementary sequence of three nucleotides (codon) on a molecule of messenger RNA.

tRNA has CCA nucleotides at the 3′ end that are meant for attaching to a specific amino acid (AA-binding site). Rest options are not true about tRNA. tRNA has four double-stranded regions.

It has an anticodon that recognizes a codon on mRNA. It looks L-shaped in a 3-D structure

Question 44. Identify A, B, C, and D in the image given below.

1. A–Variable arm, B–Amino acid arm, C–T-loop, D–Anticodon arm
2. A–Amino acid arm, B–T-loop, C–Variable arm, D–Anticodon arm,
3. A–Amino acid arm, B–Variable arm, C–Codon, D–D-loop
4. A–Amino acid arm, B–T-loop, C–Anticodon loop, D–Anticodon

Answer: 3. A–Amino acid arm, B–Variable arm, C–Codon, D–D-loop

Question 45. The similarity between the hairpin model and the clover leaf model of tRNA is that

1. Both models show three arms
2. Both models show the presence of a variable arm or lump
3. Both models show CCA nucleotide at 3′ acceptor end
4. None of the above

Answer: 3. Both models show CCA nucleotide at 3′ acceptor end

“which of the following is an initiation codon “

The hairpin model of tRNA structure was given by Hoagland and Cloverleaf was proposed by Holley. Both models show CCA nucleotide at 3′ acceptor end.

Question 46. An anticodon is the sequence of the nitrogenous bases on

1. The complementary strand of DNA, which codes for one amino acid
2. The complementary strand of mRNA, which codes for one amino acid
3. Trna molecules, where the amino acid is attached
4. tRNA molecule, which recognizes the appropriate sequence of a base on the mRNA

Answer: 4. tRNA molecule, which recognizes the appropriate sequence of the base on the mRNA

Each tRNA contains a set of three unpaired nucleotide bases called an anticodon. The anticodon of a given tRNA can bind to one or a few specific mRNA codons.

Question 47. The tRNA carrying the first amino acid in eukaryotes is denoted as

1. N-formyl methionine- tRNA
2. Val-tRNA
3. Met-tRNA
4. Amino acyl-tRNA

Answer: 3. Met-tRNA

In eukaryotes, the initiating amino acid is methionine rather than N-formylmethionine. However, as in prokaryotes, a special tRNA participates in initiation.

This aminoacyl-tRNA is called Met-tRNAi or Met-tRNAf (the subscript ‘i’ stands for initiation and ‘f ’ indicates that it can be formulated in vitro).

DNA Replication MCQs for NEET

Question 1. The multiplication of DNA is called Punjab

1. Translation
2. Replication
3. Transduction
4. Transcription

Answer: 2. Replication

The formation of new DNA from old DNA is called replication of DNA or duplication of DNA or multiplication of DNA

Question 2. DNA replication is

1. Conservative and discontinuous
2. Semiconservative and semi-discontinuous
3. Semiconservative and discontinuous
4. Conservative

Answer: 2. Semiconservative and semi discontinuous.

“dna questions “

Replication of DNA is semiconservative, i.e. from one DNA molecule, two new DNA molecules are produced and in each new DNA molecule, one strand is the parental type and another is the newly formed type.

It is semi-discontinuous because one strand is formed in a discontinuous fashion. One of the strands in each molecule synthesized is parental and the other is new.

Question 3. DNA replication is semiconservative because

1. Only one of the parent strands acts as a template
2. Both the strands of the new molecule are synthesized de novo
3. One of the strands in each molecule synthesized is parental and the other is new.
4. The daughter strands synthesized are dispersive

Answer: 3. One of the strands in each molecule synthesized is parental and the other is new.

Replication of DNA is semiconservative, i.e. from one DNA molecule, two new DNA molecules are produced and in each new DNA molecule, one strand is parental type and another is newly formed type.

It is semi-discontinuous because one strand is formed in a discontinuous fashion. One of the strands in each molecule synthesized is parental and the other is new.

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 4. Semiconservative replication of DNA was first demonstrated in

1. Streptococcus pneumoniae
2. Salmonella typhimurium
3. Drosophila melanogaster
4. Escherichia coli

Answer: 4. Escherichia coli

Semiconservative replication of DNA was first demonstrated in E. coli. According to the semiconservative mode proposed by Waston and Crick, each strand of the two double helices formed would have one old and one new strand.

DNA Replication Mcq With Answers

Question 5. One of the following statements is wrong. Identify.

1. DNA cannot produce its duplicate copies without the aid of RNA polymerase
2. DNA helps in protein synthesis
3. Rna produces complementary DNA
4. DNA replication in e. Coli is conservative

Answer: 4. DNA replication in e. Coli is conservative

The statement in option 4 is wrong and can be corrected as DNA replication in E. coli is semiconservative.

Question 6. The type of centrifugation technique that can be used to differentiate heavy DNA from normal DNA is

1. Agcl density gradient
2. Ccscl density gradient
3. Cscl density gradient
4. Kcl density gradient

Answer: 3. Cscl density gradient

Heavy DNA can be separated from normal DNA by cesium chloride (CsCl) density gradient centrifugation.

questions on dna

Question 7. Isotopes used for proving semiconservative replication of DNA are 13

1. N14 and P13
2. N14 and C14
3. N14 and N15
4. C14 and P31

Answer: 3. N14 and N15

Meselson and Stahl used 14 N and 15 N isotopes in their experiment to prove the semiconservative replication of DNA. 15N is not a radioactive isotope. It is a heavy isotope of 14N and can be separated from 14N by density gradient centrifugation

DNA Replication Mcq With Answers

Question 8. In Meselson and Stahl’s experiment, DNA extracted from the culture of one generation after the transfer from 15 n to 14n medium had a hybrid (or intermediate density).

Choose the correct reason.

1. Since the generation time of e. Coli (culture) was about 20 minutes
2. Since it would take 20 minutes for DNA translation
3. Since it would take 20 minutes for the replication of DNA to RNA (transcription)
4. Since it would take 20 minutes for the translation of RNA to protein

Answer: 1. Since the generation time of e. Coli (culture) was about 20 minutes

Option 1 is the correct reason. The replication time in E. coli is about 20 minutes.

The DNA was extracted after the interval of 20 minutes because by that time heavy 15N had been incorporated in the genetic material of E. coli and the resultant medium had a hybrid.

Question 9. Escherichia coli fully labeled with 15 n is allowed to grow in a 14n medium.

1. The two strands of DNA molecule of the first-generation bacteria have
2. Different densities and do not resemble parent DNA
3. Different density, but resemble parent DNA
4. Same density and resembles the parent DNA
5. Same density, but does not resemble parent DNA

Answer: 1. The two strands of DNA molecule of the first-generation bacteria have

After one generation in a 14N medium, the 15N labeled DNA of bacteria would settle at a level intermediate between heavy and light bands due to semiconservative DNA replication.

Thus, it had a different density and did not resemble the parent DNA.

Question 10. If a completely radioactive double-stranded DNA molecule undergoes two rounds of replication in a non-radioactive medium, what will be the radioactive status of the four resulting molecules?

1. Half the number contains no radioactivity
2. All four still contain radioactivity
3. Three out of four contain radioactivity
4. Radioactivity is lost from all four

Answer: 1. Half the number contains no radioactivity

DNA replication is semiconservative, i.e. during each replication, one of the parental strands is retained and one new daughter strand is formed.

Thus, only half of the parental DNA molecule (non-radioactive) is carried to the next generation.

In the given situation, half the number of resulting molecules would contain radioactivity whereas the other half would not contain radioactivity.

Question 11. Escherichia coli with completely radioactive DNA, was allowed to replicate in the non-radioactive medium for two generations.

The percentage of bacteria with radioactive DNA is

1. 50%
2. 12.5%
3. 100%
4. 25%

Answer: 1. 50%

E. coli with completely radioactive DNA was allowed to replicate in the non-radioactive medium for two generations.

The percentage of bacteria with radioactive DNA is 50% because, in the first generation, 100% of bacteria will have one strand radioactive, but in the next generation, only 50% of bacteria will have one radioactive strand.

questions on dna

Thus, 50% of the strands will be labeled, since DNA replication is semiconservative in nature.

NEET Biology Mcq

Question 12. In Meselson and Stahl’s experiment using e.coli culture, the duration between the appearance of equal amounts of light and heavy DNA was

1. Two generations
2. 40 Minutes
3. 20 Minutes
4. Three generations

Choose the correct option for a given statement of the question.

1. 1 and 2
2. 2 and 3
3. 3 and 4
4. 1 and 4

Answer: 1. 1 and 2

An equal amount of heavy DNA and light DNA was observed in the E. coli culture after the two generations. In forming two generations, E. coli needs about 40 minutes.

Question 13. DNA molecule with normal thymidine in both the strands was made to replicate in radioactive thymidine-rich media. After three replications what will be the number of DNA molecules with radioactive thymidine in both strands?

1. 6
2. 4
3. Only 2
4. 8

Answer: 3. Only 2

Because of the semiconservative method of DNA replication, only 2 molecules of DNA will have radioactive thymidine.

Question 14. Taylor conducted experiments to prove the semiconservative mode of chromosome replication on

1. Vinca rosea
2. Vicia faba
3. Drosophila melanogaster
4. E. Coli

Answer: 2. Vicia Faba

The semi-conservative mode of chromosome replication was proved by Taylor in Vicia faba.

NEET Biology Mcq

Question 15. The radioisotope used by Taylor was

1. Iron
2. Titanium
3. 3H
4. H3

Answer: 3. 3H

The semiconservative replication of DNA was demonstrated by Taylor et al. in 1957 with radioactive- H ( )3 H containing thymine instead of normal thymine.

Question 16. Which enzyme is required for the following process damp + atp → datp + amp?

1. Polymerase
2. Phosphorylase
3. Phosphatase
4. Pectinase

Answer: 2. Phosphorylase

The nucleotides present in the nucleoplasm in the form of monophosphates are activated into triphosphates in the presence of the enzyme phosphorylase.

questions on dna

Question 17. Deoxyribonucleoside triphosphate serves dual purposes of

1. Acting as substrate
2. Acting as an enzyme
3. Providing energy for polymerization
4. Increasing the rate of reaction.

Choose the correct option.

1. 1 and 2
2. 2 and 3
3. 3 and 4
4. 1 and 3

Answer: 4. 1 and 3

The phosphorylated nucleotides are de ATP (deoxyadenosine triphosphate), deCTP(deoxycytidine triphosphate), and deTTP (deoxythymidine triphosphate). These triphosphates of bases serve dual purposes. They act as substrates as well as provide energy for the polymerization of nucleotides by releasing energy after dissociating the phosphate group. Thus, option 4 is correct

NEET Biology Mcq

Question 18. In the given options, identify the correct equation of DNA replication.

(DNA)n + dntp ↔ (DNA)n + 1ppi
(DNA)n + 1 + dntp ↔ (DNA)n + 1ppi
(DNA)n + 2 + dntp ↔ (DNA)n + 1ppi
(DNA)n + 1 + dntp ↔ (DNA)n + 2 + ppi
Answer: 1. (DNA)n + dntp ↔ (DNA)n + 1ppi

Question 19. Replication occurs within the small opening of the DNA helix called

1. Replication fork
2. Duplication fork
3. DNA fork
4. Rna fork

Answer: 1. Replication fork

During replication, the complete DNA strand does not open at one stretch due to a very high energy requirement.

The point of separation proceeds slowly in both directions. In each direction, it gives the appearance of a Y-shaped structure called a replication fork in which replication occurs.

Question 20. The definite region of DNA where replication begins is known as

1. Origin of mutation
2. Origin of nucleotide
3. Origin of replication
4. Replication site

Answer: 3. Origin of replication

“questions about dna “

The definite region of DNA where replication begins is called the origin of replication. At the origin of replication, several enzymes like helicase, SSB, etc., are recruited to ensure replication.

Question 21. The unwinding of DNA is done by

1. Topoisomerase
2. Exonuclease
3. Helicase
4. Ligase

Answer: 3. Helicase

Helicases (unwindases) unwind the DNA helix and separate the two strands during DNA replication.

Question 22. The enzyme that breaks h2 bonds in DNA is

1. Helicase
2. Topoisomerase
3. Ligase
4. Polymerase

Answer: 1. Helicase

Enzyme helicase unwinds the DNA helix and unzips the two strands of DNA by breaking H 2 bonds between the two strands

Biology MCQ For NEET With Answers

Question 23. The enzyme DNA polymerase was discovered by

1. Kornberg
2. Okazaki
3. Watson and crick
4. Stahl and season
5. Jacob and Monod

Answer: 1. Kornberg

DNA polymerase-I (Pol-I) is an enzyme that participates in the process of prokaryotic DNA replication. Discovered by Arthur Kornberg in 1956, it was the first known DNA polymerase (and the first known kind of polymerase).

It was initially characterized in E. coli and is ubiquitous in prokaryotes.

Question 24. How many types of DNA polymerase control DNA replication in eukaryotes?

1. 2
2. 3
3. 4
4. Only one type

Answer: 2. 3

In eukaryotes, three types of DNA polymerases contribute to DNA  replication. They are polymerase α, polymerase δ and polymerase ε.

Question 25. The number of DNA polymerases in prokaryotic DNA replication is

1. One
2. Two
3. Three
4. Five

Answer: 2. Two

In prokaryotes, replication is carried out by two types of DNA polymerases, viz. 1 and 3

Biology MCQ For NEET With Answers

Question 26. The DNA polymerization rate of DNA polymerase is

1. 3.9 × 107 bp
2. 2000 Bp/s
3. 4.6 × 106 bp
4. 5000 Bp/s

Answer: 2. 2000 Bp/s

DNA replication is rapid. The replication of DNA of E. coli with 4.6 × 106bp requires 20 minutes. On average, the rate of polymerization of bases is 2000 bp per second in each direction.

Question 27. DNA polymerase is another name of

1. DNA-dependent DNA polymerase
2. DNA-dependent RNA polymerase
3. Rna-dependent RNA polymerase
4. Rna-dependent DNA polymerase

Answer: 1. DNA-dependent DNA polymerase

DNA polymerases are also called DNA-dependent DNA polymerases

Biology MCQ For NEET With Answers

Question 28. The enzyme that reduces the tension during the unwinding of the DNA helix in front of the replication fork is

1. Topoisomerase
2. Helicase
3. Ligase
4. Polymerase
5. Endonuclease

Answer: 1. Topoisomerase

The two strands of DNA are joined with the help of H-bonds between the strands. Topoisomerase-I is specialized to form nicks or breaks in the double helix and helps to separate the DNA strands. Thus, it reduces the tension in strands during the unwinding of the DNA helix

Question 29. Identify the protein that stabilizes the separated complementary strands.

1. Ligase
2. Ssbps
3. DNA polymerase
4. Dsbps

Answer: 2. Ssbps

Single Strand Binding Proteins (SSBPs) prevent the recoiling of separated strands and stabilize them.

“dna replication is “

Question 30. The function of helix-destabilizing proteins is to

1. Keep uncoiled strands of DNA apart
2. Resist uncoiling of DNA under normal conditions
3. Repair DNA molecules during replication
4. Keep DNA helix tightly coiled

Answer: 1. Keep uncoiled strands of DNA apart

Helix-destabilizing proteins are any protein that binds to single-stranded regions of duplex DNA and thereby, causes the unwinding of the helix, e.g. helicase. Thus, it helps to keep uncoiled DNA strands far apart.

Question 31. In DNA replication, the primer is

1. DNA primer
2. Rna primer
3. Both DNA and RNA
4. None of the above

Answer: 2. Rna primer

In DNA replication, RNA primer is required to initiate polynucleotide synthesis which is then elongated by DNA polymerase.

Question 32. Rna primer is a must for the initiation of DNA duplication as it

1. Adds nucleotides to the template strand
2. Activates DNA polymerase
3. Activates RNA polymerase
4. Stops DNA duplication

Answer: 1. Adds nucleotides to the template strand

The RNA primer attaches itself at the end of the template strand and adds the new nucleotides to it.

To initiate the formation of a new strand on the template strand, DNA polymerase needs the presence of RNA primer (short RNA segment) because the former cannot initiate polynucleotide synthesis, but can elongate it.

Biology MCQs with answers for NEET

Question 33. …………… Help in the removal of Rna primers.

1. DNA polymerase-1
2. Rna polymerase-2
3. DNA polymerase-2
4. DNA polymerase-3

Answer: 1. DNA polymerase-1

RNA primers are removed by DNA polymerase-I. It also plays a role in the repair of DNA.

Question 34. Ligase enzyme functions in

1. Denaturation of DNA
2. Digestion of lipids
3. Joining bits of DNA
4. Joining two chromosomes

Answer: 3. Joining bits of DNA

DNA polymerases can only catalyze DNA synthesis in 5′ and 3′ directions.

On the complementary strand, replication is discontinuous, resulting in small DNA segments called Okazaki fragments, which are joined by ‘The DNA ligase enzyme.

Question 35. Protein helping in the opening of DNA double helix in the form of the replication fork is

1. DNA gyrase
2. DNA polymerase-1
3. DNA ligase
4. DNA primase

Answer: 1. DNA gyrase

DNA gyrase participates in the unwinding and relieving super-coiling of DNA helix in the form of a replication fork during replication. It is a type of topoisomerase-2 enzyme.

Question 36. The Okazaki fragments in DNA chain growth cbse

1. Polymerise in the 3′- 5′ direction and forms replication fork
2. Prove the semiconservative nature of DNA replication
3. Polymerise in the 5′- 3′ direction and explain 3′-5′ DNA replication
4. Result in transcription

Answer: 3. Polymerise in the 5′- 3′ direction and explain 3′-5′ DNA replication

Okazaki fragments are polymerized in a 5 3′− ′ direction by DNA polymerase enzyme. Their replication is carried out in 3 5′ ′- the direction of the template strand, away from the replication fork

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Question 37. The new strand synthesized in small pieces and then joined together during DNA replication is called

1. Dead strand
2. Lagging strand
3. Leading stand
4. All of these

Answer: 2. Lagging strand

In template strands with polarity 5′-3′, DNA polymerase is not able to synthesize new strands in the 3 5′ ′- direction.

This strand is the lagging strand and on this strand, synthesis takes place discontinuously in small pieces called Okazaki fragments.
These are later joined by DNA ligase.

Question 38. During DNA replication, Okazaki fragments are used to elongate

1. The leading strand toward the replication fork
2. The lagging strand towards the replication fork
3. The leading strand away from the replication fork
4. The lagging strand away from the replication fork

Answer: 4. The lagging strand away from the replication fork

Okazaki fragments synthesized on a 5′-3′ DNA template, join to form a lagging strand that grows in 3 5-′ ′ direction, away from the replication fork

Question 39. Consider the following statements.

The new DNA strand is synthesized by the addition of nucleotides at the 5′–oh group.
DNA synthesis occurs in the 5′-3′ direction.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 2. Statement 1 is incorrect, but 2 is correct

The incorrect statement can be corrected as the Synthesis of a new DNA strand takes place by the addition of DNA nucleotides to the 3′ – OH group of the last ribonucleotide of the RNA primer.

This synthesis takes place in the 5′ and 3′ directions and is catalyzed by DNA polymerase.

Biology MCQs with answers for NEET

Question 40. During DNA replication, the term leading strand is applied to the one that replicates in

1. 5′ → 3′ Direction discontinuously
2. 3′ → 5′ Direction continuously
3. 5′ → 3′ Direction continuously
4. 3′ → 5′ Direction discontinuously

For long DNA molecules, the two strands of DNA cannot be separated in its entire length due to the requirement of

1. Enzymes
2. High energy
3. RNA
4. Phosphate and nucleotide

Answer: 3. RNA

When the double helix of DNA unwinds, DNA replication on one of the two strands (3′-5′ strand) can easily proceed continuously in the 5′-3′ direction. This is the leading strand

Question 42. Choose the sequence in which the following enzymes are used in DNA replication.

1. Helicase
2. Primase
3. Ssbps
4. DNA polymerase
5. DNA ligase

Choose the correct option.

1. 1 → 4 → 4 → 3 → 2
2. 1 → 2 → 3 → 4 → 5
3. 1 → 3 → 2 → 4 → 5
4. 1 → 4 → 3 → 2 → 5

Answer: 3. 1 → 3 → 2 → 4 → 5

A helicase unwinds and splits the DNA. Thereafter, Single-Strand Binding Proteins (SSBPs) swiftly bind to the separated DNA, thus preventing the strands from reuniting.

A primase then generates an RNA primer which initiates the synthesis of DNA.

Question 43. Which one of the following correctly represents the manner of replication of DNA?

Answer: 4.

When the double helix of DNA unwinds, DNA replication on one of the two strands (3′-5′ strand) can easily proceed continuously in the 5′-3′ direction. This is the leading strand.

Question 44. Which of the following statements is incorrect?

1. DNA replication is the process by which DNA makes a copy of itself during cell division
2. The first step in DNA replication is to ‘unzip’ the double helix structure of the DNA molecule
3. DNA replication occurs in all living organisms
4. All of the above is incorrect

Answer: 1. DNA replication is the process by which DNA makes a copy of itself during cell division

The statement in option (a) is incorrect and can be corrected as DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule.

It occurs during the S-phase of the cell cycle. Rest statements are correct

Question 45. All of the following statements characterize DNA replication except

1. The second DNA strand is in the form of Okazaki segments
2. DNA is synthesised in 3′ to 5′ direction in one strand and 5′ to 3′ in another
3. The growth of the DNA chain is discontinuous
4. The overall growth of the DNA chain is bidirectional

Answer: 2. DNA is synthesised in 3′ to 5′ direction in one strand and 5′ to 3′ in another

All given statements characterize DNA replication except the statement in option

Because DNA polymerase synthesizes DNA in a 5′ to 3′ direction only because DNA polymerase acts on the 3′OH of the existing strand for adding free nucleotides.

Both the Okazaki fragments and leading strand are synthesized in a 5′- 3′ direction. The discontinuous assembly of lagging strands enables

Question 46. During the replication of a bacterial chromosome DNA synthesis starts from a replication origin site and RNA primers are involved
Is facilitated by telomerase

1. Moves in one direction of the site
2. Moves in a bidirectional way

Answer: 4. Moves in a bidirectional way

Replication begins at the ori or origin of replication and proceeds on both sides from the ori, i.e. it is bidirectional. Unidirectional replication is rare.

Question 47. E. Coli has only 4 6 10. × 6 Base pairs and completes the process of replication within 18 minutes, then the average rate of polymerization is approximately

1. 2000 Bp/s
2. 3000 Bp/s
3. 4000 Bp/s
4. 1000 Bp/s

Answer: 3. 4000 Bp/s

E. coli has 4 6 10. × 6 base pairs. It completes the replication process in about 18 to 20 minutes, i.e. 18 60× seconds. Rate of polymerization or approximately 4000 bp/sec Thus, the correct option is (c)

Biology MCQ For NEET With Answers RNA World

Question 1. TO Diener discovered

1. Free infectious dna cbse aipmt 2009
2. Infectious protein
3. Bacteriophage
4. Free infectious RNA

Answer: 4. Free infectious RNA

Theodor Otto Diener discovered the Potato Spindle Tuber Viroid (PSTVd), the first viroid ever identified in 1971. PSTVd is a small, circular RNA molecule.

Dr Diener discovered that the pathogen causing potato spindle tuber disease is not a virus, but a much smaller, free infectious RNA molecule.

“dna questions “

Question 2. Who was awarded the Nobel Prize for synthesis of RNA in 1959?

1. S Ochoa
2. H Khorana
3. A Kornberg
4. Nirenberg

Answer: 1. S Ochoa

The Nobel Prize for artificial synthesis of RNA was given to S Ochoa (1959).

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 3. RNA acts as genetic material in

1. Bacteria
2. Virus
3. Fungi
4. All of these

Answer: 2. Virus

RNA acts as genetic material only in viruses like polioviruses, HIV, etc.

Question 4. Molecules which play the key role in the transfer of genetic information during protein synthesis are ……………..

1. DNA
2. RNA
3. Nucleic acid
4. Lipids

Answer: 2. RNA

DNA has all the information which is confined to the nucleus, it is only transferred with the help of RNA during protein synthesis.

“questions on dna “

RNA also has a diverse function in the body which includes the enzymatic activity of ribozymes and the storage of genetic information in RNA viruses.

Biology MCQ For NEET With Answers

Question 5. The backbone of RNA consists of which of the following sugars?

1. Deoxyribose
2. Ribose
3. Sucrose
4. Maltose

Answer: 2. Ribose

The backbone of RNA is made up of ribose sugar (C5 H10 O5 )

Question 6. Ribose sugar is present in Karnataka CET 2009

1. RNA polymerase and ATP
2. RNA and ATP
3. RNA polymerase, RNA and ATP
4. RNA only

Answer: 2. RNA and ATP

Ribose (d-ribose) is a type of simple sugar or carbohydrate that our bodies make. D-ribose is a naturally occurring monosaccharide within the pentose pathway that assists in ATP production.

It is a 5-carbon chain (also called aldopentose) and is a key component of DNA, Ribonucleic Acid (RNA), acetyl coenzyme-A and ATP.

Biology MCQ For NEET With Answers

Question 7. Viruses having RNA genomes have a shorter lifespan mutate and evolve faster because

1. RNA is unstable, hence mutates at a faster rate
2. RNA is stable and, hence mutates at a faster rate
3. RNA is stable and mutates at a slower rate
4. RNA is unstable and mutates at a slower rate

Answer: 1. RNA is unstable, hence mutates at a faster rate

Both DNA and RNA are able to mutate. RNA being unstable mutates at a faster rate. Consequently, viruses having RNA genomes and shorter lifespans mutate and evolve at a faster rate

Question 8. Genetic information transfers from the nucleus to the cytoplasm by MP PMT 2005

1. DNA
2. RNA
3. Lysosome
4. All of these

Answer: 2. RNA

The type of RNA that contains the genetic information for making a protein is called messenger RNA

Biology MCQs with answers for NEET

Question 9. A maximum amount of RNA is present in

1. Cytoplasm
2. Nucleus
3. Ribosomes
4. Mitochondria

Answer: 3. Ribosomes

The maximum amount of RNA in a cell is rRNA, forming 80% of the total cellular RNA. It is found associated with the ribosomes

Question 10. Consider the following statements.

Purines in RNA are adenine and guanine.
RNA contains two pyrimidine bases, viz. thymine and cytosine.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 3 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 1. Statement 1 is correct, but 2 is incorrect

Statement I is correct, but II is incorrect. The incorrect statement can be corrected as In the case of DNA, the pyrimidines are cytosine (C) and thymine (T), but in the case of RNA, thymine is replaced by uracil (U). Thus, RNA does not contain thymine

Question 11. In the double-stranded region of RNA, the pairing pattern is

1. A=T, C=G
2. A=U, C=G
3. A=G, C=T
4. A=C, G=U

Answer: 2. A=U, C=G

Double-stranded RNA (dsRNA) is RNA with two complementary strands. In it, adenine base pairs with uracil and guanine pairs with cytosine

Biology MCQs with answers for NEET

Question 12. Purine to pyrimidine ratio in RNA is not 1:1 because

1. All the nitrogenous bases are not paired
2. They are of three types
3. DNA is absent
4. DNA is in the extranuclear part

Answer: 1. All the nitrogenous bases are not paired

Chargaff’s rule does not hold good for RNA. RNA is single-stranded and nitrogenous bases are unpaired. Hence, the purine-to-pyrimidine ratio is not 1:1 always and thus, it does not follow Chargaff’s rule of base pairing.

Question 13. Chemically, DNA differs from RNA as

1. Uracil is Present In DNA and Thymine In Rna Deoxyribose And Thymine is Present In
2. Dna And Ribose And Uracil In Rna
3. Ribose And Thymine In Dna And Deoxyribose And Uracil In Rna
4. Deoxyribose In Dna And Ribose In Rna

Answer: 2. Ribose And Thymine In DNA and Deoxyribose And Uracil In Rna

RNA is very similar to DNA but differs in a few important structural details.

RNA is single-stranded, while DNA is double-stranded. Also, RNA nucleotides contain ribose sugars, while DNA contains deoxyribose sugar.

RNA predominantly contains uracil instead of thymine present in DNA

Biology MCQs with answers for NEET

Question 14. The two ends of an RNA molecule are identified as

1. 5′ End and 3′ end
2. N-terminal end and c-terminal end
3. Reducing end and non-reducing end
4. Head end and tail end

Answer: 1. 5′ End and 3′ end

The two ends of RNA are designated as 5′ end and 3′ end. The 5′ end has a free phosphate group whereas the 3′ end has a free hydroxyl group.

“questions about dna “

Question 15. Consider the following statements.

1. RNA is a polymer of ribonucleotides.
2. Ribonucleotides in RNA are linked together by 5 5′− phosphodiester linkages.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement I is incorrect, but 3 is correct
3. Both statements 1 and 1 are correct
4. Both statements 1 and 2 are incorrect

Answer: 1. Statement 1 is correct, but 2 is incorrect

Statement 1 is correct, but II is incorrect. The incorrect statement can be corrected as Ribonucleic acid (RNA) is a polymer of purine and pyrimidine ribonucleotides linked together by 3′-5′ phosphodiester bridges analogous to those in DNA.

Question 16. Name the RNA molecule which is used to carry genetic information copied from DNA.

1. tRNA
2. mRNA
3. rRNA
4. snRNA

Answer: 2. Messenger (m) RNA carry genetic information from DNA to protein molecules.

It carries the message to the ribosome.

Question 17. mRNA is a

1. Linear molecule
2. Circular molecule
3. M-shaped molecule
4. Both (2) and (3)

Answer: 1. Linear molecule

mRNA is a linear molecule composed of four types of smaller molecules called ribonucleotide bases, adenine (A), cytosine (C), guanine (G) and uracil (U).

Each ribonucleotide base consists of a ribose sugar, a phosphate group and a nitrogenous base.

Question 18. mRNA forms about ………… of the total cellular RNA.

1. 1-2%
2. 10-11%
3. 8-9%
4. 3-5%

Answer: 4. 3-5%

mRNA accounts for only 3-5% of the total cellular RNA although the the actual amount depends on the cell type and its physiological state.

Question 19. Which of the following RNAs should be most abundant in animal cells?

1. rRNA
2. tRNA
3. mRNA
4. miRNA

Answer: 1. rRNA

rRNA is the most abundant type of RNA found in animal cells. It constitutes almost 80% of the total RNA of the cell. It should be most abundant because it is responsible for coding and producing all the proteins in cells

Question 20. rRNA is synthesised in

1. Nucleus Odisha Jee 2006
2. Nucleolus
3. Cytoplasm
4. Endoplasmic reticulum

Answer: 2. Nucleolus

Ribosomal RNA (rRNA) is a component of the ribosomes, the protein synthesis factories in the cell. Eukaryotic ribosomes contain four different rRNA molecules, i.e. 18S, 5.8S, 28S and 5S rRNA.

Three of the rRNA molecules are synthesised in the nucleolus and one is synthesised elsewhere.

Question 21. Which of the following rRNAs acts as structural RNA as well as ribozyme in bacteria?

1. 5 S rRNA
2. 18 S rRNA
3. 23 S rRNA
4. 5.8 S rRNA

Answer: 3. 23 S rRNA

23S rRNA is a component of the larger subunit of the ribosome and it acts as peptidyl transferase (ribozyme)

Question 22. Which of the following RNA molecules convert information stored in the nucleic acid to protein?

1. mRNA
2. snRNA
3. rRNA
4. tRNA

Answer: 4. tRNA

Transfer RNA (tRNA) plays a key role in protein biosynthesis and is known as adapter tRNA

Question 23. mRNA, rRNA and tRNA are

1. Genetic rna
2. Non-genetic rna
3. Both (1) and (2)
4. Present in all viruses

Answer: 2. Non-genetic rna

Non-genetic RNA is an RNA molecule which does not act as a genetic material. There are three types of non-genetic RNA. They are mRNA, rRNA and tRNA.

These RNAs are produced on DNA templates by a process called transcription.

Question 24. The element absent in RNA is AMU 2005

1. Nitrogen
2. Sulphur
3. Oxygen
4. Hydrogen

Answer: 2. Sulphur

Components of nucleic acids are constructed from five elements, i.e. carbon, hydrogen, oxygen, nitrogen, and phosphorus. Sulphur is not found in RNA.

Question 25. Some RNA viruses carry a gene for an enzyme that uses viral RNA as a template in the synthesis of DNA.

1. This enzyme is Punjab PMET 1995
2. RNA replicase
3. Viral nuclease
4. Rna polymerase
5. Reverse transcriptase

Answer: 3. Rna polymerase

RNA Polymerase or Ribo nucleic Acid Polymerase (RNAP) is a multisubunit enzyme that catalyses the process of transcription where an RNA polymer is synthesised from a DNA template.

This RNA strand is called the primary transcript and it needs to be processed before it gets functional inside the cell.

Question 26. The linkage that joins two adjacent nucleotides in RNA is AMU 2004

1. Phosphate ester
2. Phosphodiester
3. Phosphate anhydride
4. N-glycoside

Answer: 2. Phosphodiester

A phosphodiester bond is a group of strong covalent bonds between the the phosphate group of the 5th carbon of one nucleotide and the hydroxyl group of the 3rd carbon of another nucleotide

Question 27. Ribozymes are

1. RNA acting as enzymes
2. DNA acting as enzymes
3. DNA acting as molecular scissors
4. RNA acting as molecular scissors

Answer: 1. RNA acting as enzymes

“questions about dna “

RNA that function as enzymes are called ribozymes. For example, in splicing (removal of introns), protein synthesis (23S RNA), etc

Question 28. Which statement about RNA is true?

1. It is a simple, straight or coiled, single-stranded molecule
2. Components of RNA are ribose sugar, phosphate and N-bases.
3. The Strand of RNA is a long chain of nucleotides joined by a phosphodiester bond.
4. Base pairing between complementary bases occurs on the coiling or folding of RNA molecules.

Choose the correct option.

1. 1, 2 and 3 are correct
2. 1, 2 and 4
3. 1 and 4
4. 1, 2, 3 and 4

Answer: 4. Base pairing between complementary bases occur on the coiling or folding of RNA molecule.

Question 29. The sequence of nucleotides AUGCUUCUC indicates that it is a segment of MHT CET 2014

1. Sense strand of DNA
2. Antisense strand of dna
3. Rna
4. Polypeptide chain

Answer: 3. Rna

Uracil is exclusively found in RNA. Thus, the given segment is RNA.

Question 30. Processes like metabolism, splicing and translation revolved around

1. DNA
2. RNA
3. Protein
4. Nucleus

Answer: 2. RNA

RNA was the first genetic material. There is now enough evidence to suggest that essential life processes such as metabolism, translation, and splicing were based on RNA.

It acts as a genetic material as well as a catalyst. There are some important biochemical reactions in living systems that are catalysed by RNA catalysts and not by protein enzymes.

Biology MCQ For NEET With Answers The Search For Genetic Material

Question 1. Who introduced the transforming principle?

1. Frederick Griffith
2. Oswald Avery
3. Colin MacLeod
4. Maclyn McCarty

Answer: 1. Frederick Griffith

The transforming principle (Griffith’s experiment) was introduced by Frederick Griffith (1920). He conducted a series of experiments with Streptococcus pneumoniae and found that a living organism (bacteria) had changed in physical form.

Question 2. The experimental organism used by Frederick and Griffith was

1. Variola virus
2. Streptococcus pseudopneumoniae
3. Actinomycetes
4. Streptococcus pneumoniae

Answer: 4. Streptococcus pneumoniae

“molecular basis of inheritance “

The transforming principle (Griffith’s experiment) was introduced by Frederick Griffith (1920). He conducted a series of experiments with Streptococcus pneumoniae and found that a living organism (bacteria) had changed in physical form.

Read And Learn More: NEET Biology Multiple Choice Question And Answers

Question 3. Transfer of DNA from one bacterium to another by contact is known as

1. Conjugation
2. Transformation
3. Transduction
4. Transcription

Answer: 1. Conjugation

Conjugation is the process by which one bacterium transfers genetic material to another through direct contact. During conjugation, one bacterium serves as the donor of the genetic material and the other serves as the recipient.

The donor bacterium carries a DNA sequence called the fertility factor or F-factor.

Biology MCQ For NEET With Answers

Question 4. Consider the following statements.

1. S. pneumoniae produce two types of colonies, viz. smooth and rough.
2. S-type bacteria form smooth colonies due to the absence of a polysaccharide coat.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 1. Statement 1 is correct, but 2 is incorrect

Statement I is correct, but II is incorrect. The incorrect statement can be corrected as S-type bacteria form a smooth colony because they possess polysaccharide (mucus) coat around themselves, whereas R-type bacteria do not form any covering around themselves

Question 5. S-type strain streptococcus pneumoniae is

1. Capsulated, virulent, smooth
2. Non-capsulated, avirulent, rough
3. Capsulated, avirulent, rough
4. Non-capsulated, virulent, smooth

Answer: 1. Capsulated, virulent, smooth

An S-type strain of S. pneumoniae is capsulated, virulent and smooth in appearance

“molecular biology mcq “

Question 6. What was unique in Griffith’s experiments?

1. DNA was found to be the genetic material
2. RNA was found to be the genetic material
3. Something from dead organisms could change the living cells
4. The genetic makeup of dead and living organisms was the same

Answer: 3. Something from dead organisms could change the living cells

In Griffith’s experiment, Griffith found that something from a dead organism could change the living cells.  From his experiment, he showed that dead S-bacteria changed or transformed the R-bacteria into S-type.

Biology MCQ For NEET With Answers

Question 7. What happened when heat-killed S cells along with live R cells were injected into mice?

1. Mice survived and showed live S cells
2. Mice died and showed live S cells
3. Mice survived and showed live R cells
4. Mice died and showed live R cells

Answer: 2. Mice died and showed live S cells

As a part of his experiments, Griffith tried injecting mice with heat-killed S bacteria. Unsurprisingly, the heat-killed S bacteria did not cause disease in mice.

However, when harmless R bacteria were combined with harmless heat-killed S bacteria and injected into a mouse, the mouse developed pneumonia and died. When Griffith took a blood sample from the dead mouse, he found that it contained living S bacteria.

Question 8. Choose the statements that are correct about Griffith’s experiment.

1. S-strain has a capsule.
2. The mouse will die if injected with living S-strain.
3. The mouse will die if injected with living R-strain.
4. The transforming principle is associated with a capsule of S-strain.
5. Transformation of the R-strain into the S-strain can take place in a test tube.

Choose the correct answer

1. 1 and 2
2. 3 and 4
3. 1, 2 and 5
4. 3, 4 and 5

Answer: 3. 1 and 2

Statements 1, 2 and 5 are correct, while 3 and 4 are incorrect. These can be corrected as In Griffith’s experiment, mice did not die when living if injected with R-strain because R-strain is non-virulent.

The transforming principle is associated with the genetic material (transforming material) of S-bacteria.

“which one of the following is not applicable to rna “

Question 9. The transformation experiment of Griffith was proved by

1. Griffith himself
2. Avery, MacLeod, McCarty
3. Meselson
4. Beadle and Tatum

Answer: 2. Avery, MacLeod, McCarty

Oswald Avery, Colin MacLeod and Maclyn McCarty (1933-44) worked to determine the biochemical nature of ‘the transforming principle in Griffith’s experiment’.

They purified biochemicals like proteins, DNA, RNA, etc., from the heat-killed S-cell to observe which one could transform live R-cells into S-cells.

They discovered that DNA alone from S-bacteria caused the R-bacteria to transform.

Digestion with DNase inhibited transformation, suggesting that DNA is the heredity material

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Question 10. The result of the following reaction experiments carried out by Avery et at., on Streptococcus pneumoniae, has proved conclusively that DNA is the genetic material.

1. Live R-strain + DNA from S-strain + RNase
2. Live R-strain + DNA from S-strain + DNase
3. Live R-strain + Denatured DNA of S-strain + protease
4. Heat killed R- strain + DNA from S-strain + DNase

Answer: 2. Live R-strain + DNA from S-strain + DNase

R-strain is rough and harmless, while S-strain is a smooth and virulent form of Streptococcus pneumoniae.

In their experiment, Avery et al. found out that only when DNA from S-type bacteria was added to a culture of R-type bacteria, R-type got converted to an S-type strain.

This transformation of R into S-type did not occur with the addition of carbohydrates or protein from S-type bacteria. Also, when the DNase enzyme was added, i.e. live R-strain + DNA (S-strain) + DNase, the transformation did not occur. It proved conclusively that DNA, indeed is the genetic material.

Question 11. What is the difference in the transformation experiment of Griffith and Avery, MacLeod and McCarty?

1. Use of heat-killed R-type
2. Use of deoxyribonuclease
3. Use of proteins
4. Use of S-type

Answer: 2. Use of deoxyribonuclease

The use of deoxyribonuclease (DNase) enabled Avery, MacLeod and McCarty to prove that DNA is the genetic material. This enzyme was not used by Griffith in his experiments

“bank of biology class 12 molecular basis of inheritance “

Question 12. The final proof for DNA as the genetic material came from the experiments of

1. Griffith
2. Hershey and Chase
3. Avery, MacLeod and McCarty
4. Hargobind Khorana

Answer: 2. Hershey and Chase

Hershey and Chase gave unequivocal proof that DNA is genetic material.

Question 13. Which experiment proved that DNA is the genetic material?

1. Transformation Haryana PMT 2003
2. Transduction
3. Infection of tobacco with TMV
4. Lederberg’s Replica experiment

Answer: 1. Transformation Haryana PMT 2003

The unequivocal proof that DNA is genetic material was given by a transformation experiment performed by Alfred Hershey and Martha Chase in 1952.

They worked with viruses that infect bacteria called bacteriophages. Hershey and Chase used 35 S and 32 P to prove that DNA is genetic material.

Question 14. Match the following columns.

Answer: 3. A–2, B–3, C–4, D–5, E–1

Question 15. Experiments which proved DNA to be hereditary material were conducted on Manipal 2008

1. Drosophila
2. Bacteria
3. Mice
4. Bacteriophages

Answer: 4. Bacteriophages

The unequivocal proof that DNA is genetic material was given by a transformation experiment performed by Alfred Hershey and Martha Chase in 1952.

They worked with viruses that infect bacteria called bacteriophages. Hershey and Chase used 35 S and 32 P to prove that DNA is genetic material.

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Question 16. In Hershey and Chase’s experiment, bacteriophage nucleic acids were labelled as

1. 32P labelled phosphate
2. 3H labelled H O2
3. 35S labelled sulphate
4. 14C labelled CO2

Answer: 1. 32P labelled phosphate

AD Hershey and Martha Chase (1952) grew cultures of Escherichia coli. One culture was treated with radioactive sulphur, 35 S which had a bacteriophage protein coat. The other culture was treated with radioactive phosphorus, 32 P.

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Radioactive sulphur got incorporated into sulphur-containing amino acids(cysteine and methionine) and therefore, became part of bacterial protein.

Radioactive phosphorus got incorporated into nucleotides, which formed the nucleic acids, mostly DNA. So, bacteriophage nucleic acid was labelled as 32 P phosphates.

Question 17. The bacteriophage protein coat was labelled by ……… in the Hershey and Chase experiment.

1. 35S labelled sulphur
2. 32S labelled sulphate
3. The 30S labelled sulphur
4. 32P labelled sulphate

Answer: 1. 35S labelled sulphur

AD Hershey and Martha Chase (1952) grew cultures of Escherichia coli. One culture was treated with radioactive sulphur, 35 S which had a bacteriophage protein coat.

The other culture was treated with radioactive phosphorus, 32 P.

Radioactive sulphur got incorporated into sulphur-containing amino acids (cysteine and methionine) and therefore, became part of bacterial protein.

Radioactive phosphorus got incorporated into nucleotides, which formed the nucleic acids, mostly DNA. So, bacteriophage nucleic acid was labelled as 32 P phosphates.

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Question 18. In Hershey and Chase’s experiment, radioactive 32 P was used to culture bacteriophage which resulted in radioactive Kerala

1. Viral DNA
2. Bacterial capsule
3. Viral protein
4. The plasma membrane of bacteria
5. Protein capsule of bacteriophage

Answer: 1. Viral DNA

Hershey and Chase grew some viruses on a medium that contained radioactive phosphorus 32 P and some others on a medium that contained radioactive sulphur ( 35 S).

Viruses grown in the presence of radioactive phosphorus contain radioactive DNA, but not radioactive protein because DNA contains phosphorus but the protein coat lacks it.

Similarly, viruses grown on radioactive sulphur contained radioactive protein coat but not radioactive DNA because DNA does not contain sulphur.

Question 19. Hershey and Chase used 35 S and 32 P to prove that DNA is the genetic material. Their experiments proved that DNA is genetic material because

1. Progeny bacterial cell retained 32P, but not 35S
2. Retention of 32P in progeny bacterial cells indicated that DNA was passed on
3. Loss of 35S in progeny bacterial cells indicated that proteins were not passed on
4. All of the above

Answer: 4. All of the above

Hershey and Chase used 35 S and 32 P to prove that DNA is genetic material because Progeny bacterial cells retained 32 P, but not 35 S. Retention of 32 P in progeny bacterial cells indicated that DNA was passed on.

Loss of 35 S in progeny bacterial cells indicated that proteins were not passed on and it remained in supernatant only.

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Question 20. Hershey was awarded the Nobel Prize in 1969 for providing

1. X-ray crystallographic technique
2. Helical coiling of DNA
3. Proof of DNA as genetic material
4. Semiconservative DNA replication

Answer: 3. Proof of DNA as genetic material

Hershey shared the 1969 Nobel Prize in Physiology or Medicine with Max Delbrück and Salvador Luria for their ‘discoveries to prove that DNA is genetic material.

Question 21. Consider the following statements about the Hershey and Chase experiment.

1. Sulphur is present in proteins, but not in DNA.
2. Phosphorus is present in DNA, but not in protein.

Choose the correct option.

1. Statement 1 is correct, but 2 is incorrect
2. Statement 1 is incorrect, but 2 is correct
3. Both statements 1 and 2 are correct
4. Both statements 1 and 2 are incorrect

Answer: 3. Both statements 1 and 2 are correct

Hershey and Chase grew some viruses on a medium that contained radioactive phosphorus 32 P and some others on a medium that contained radioactive sulphur ( 35 S).

Viruses grown in the presence of radioactive phosphorus contain radioactive DNA, but not radioactive protein because DNA contains phosphorus but the protein coat lacks it.

Similarly, viruses grown on radioactive sulphur contained radioactive protein coat but not radioactive DNA because DNA does not contain sulphur.

Question 22. In Hershey-Chase’s experiment, when the radioactive viruses were allowed to infect E. coli, what was observed?

1. E. coli which was infected by viruses with radioactive DNA became radioactive.
2. E. coli which was infected by viruses with radioactive protein did not become radioactive.
3. E. coli which was infected by viruses with radioactive DNA did not become radioactive.
4. E. coli which was infected by viruses with radioactive protein became radioactive.

Choose the correct option.

1. 1 and 2 were observed
2. 2 and 3 were observed
3. 3 and 4 were observed
4. 1 and 4 were observed

Answer: 1. 1 and 2 were observed

Hershey and Chase found that when bacteriophages containing 32 P or radioactive DNA, were allowed to infect non-radioactive bacteria, all the infected cells became radioactive and in fact, much of the radioactivity was passed on to the next generation of E. coli bacteria.

Question 23. DNA with labelled thymidine is added to a medium where Escherichia coli is growing. After 5 minutes of growth

1. All the DNA strands of parents and daughters will show DNA with labelled thymidine
2. Only parental strands will show thymidine-labelled DNA
3. All the strands of daughters will be thymidine-labelled
4. Half the daughter strands will have labelled and half strands without labelled thymidine

Answer: 3. All the strands of daughters will be thymidine-labelled

All the strands of the daughter cell would be thymidine labelled because DNA acts as genetic material.

Question 24. A molecule to acts as a genetic material has the following properties Kerala.

1. Should be able to replicate it.
2. Should be structurally more stable.
3. Should be more reactive and labile.
4. Should provide scope for slow changes.

Choose the correct option.

1. 1, 2 and 3 are correct
2. 3 alone is correct
3. 3 and 4 are correct
4. 1, 2 and 4 are correct
5. 1 alone am correct

Answer: 4. 1, 2 and 4 are correct

For a molecule to act as a genetic material must fulfil the following criteria

It should be able to replicate or form its carbon copies. Genetic material should be able to express itself through the formation of specific biochemicals.

There are occasional changes or mutations in the structure and functioning of its genes which are of permanent nature and inheritable.

Mutations are essential for evolution and adaptability. It should be stable both chemically and physically. Thus, statement III is incorrect, while the other three are correct

Question 25. Identify the correct statement.

1. DNA is dependent on RNA for the synthesis of proteins
2. DNA and RNA both function as genetic material
3. DNA is more stable and is the preferred genetic material but for the transmission of genetic information, RNA is better
4. All of the above

Answer: 4. All of the above

All the given statements are correct.